See, if Wonder Woman had a dedicated editor that might be something that would be ironed out and agreed upon but as she doesn't, this is something that differs quite significantly from writer to writer.
Back in the golden age she was born some time between the 1600s and 1900. In Azzarellos run she was born less than forty years ago. In Geoff Johns Justice League run she was born five thousand years ago. In Ruckas shes three thousand years old. So take your pick I suppose.
A huge clusterbleep.
Okay so Geoff Johns in establishing the twins thing showed Hippolyta giving birth minutes after arriving on the island for the first time thousands of years ago. This was also at the same time that Myrina Black gave birth to Grail.
We see Myrina leave the island with Grail and the first people she finds are wearing ancient clothing and use candles for lighting so we can safely say this is some time back. We also get a look at her Amazon-cave where she kept artifacts across the centuries from past battles protecting the world in secret.
Robinson kept this, but established that jason was raised in modern times and is at most thirty years old. Which matches Azarellos run where the Amazons were all mortal and aged normally....But completely screws over any consistency with Johns run because this would mean that the Amazons have only been on their island for a few decades at most.
So to sum it up ¯\_(ツ)_/¯
The Fountain of Youth was only around as an explanation in the Golden Age, right? Otherwise it's just that the island is magical and as long as they live there they are immortal.
The island is very obviously magical in the movies, that and they were created by Gods. it doesn't really need to spell things out any more than that.
Its differed.
Golden age it was the fountain of youth which must be drunk from once a day otherwise you begin aging normally.
Silver age it was established to be a blessing of the gods and that by taking the oath to become an Amazon you get immortality unless you break your oath which included staying on the island. This version had some leeway because you could get permission from the gods to make an exception. This also established that Wonder Woman was immortal off the island so long as she fulfilled her oath as Wonder Woman.
Post Crisis the Amazons were likewise blessed by the gods, with the Bana specifically losing their immortality because they cast aside the Greek gods. (never understood why they didn't get an immortality package out of the Egyptian pantheon.)
new 52 gaze us Azzarellos mortal Amazons and Finch established magic ruby that brings immortality to anyone around it.
I don't recall the island itself to grant any special powers to its residents.
Oh and theres Legend of Wonder Woman where the original generation of Amazons are immortal and future generations of Amazons are mortal.
And Wonder Woman warbringer where the island existed in a time bubble where a year on the island was a hundred years in the outside world.
Maybe not the island itself, but it's been pretty consistent that whatever divine blessings they get to make them immortal are actually on the island (the Fountain of Youth or the ruby) or connected to it in some way (Silver Age staying on the island unless there is special permission from the Gods). There is also the fact that the island itself is generally shown as being mystically shielded to prevent access, so it's not a normal location. The film explicitly shows Steve and the Germans passing through some mystical barrier to get there. Combined with the Amazons being created in the age of the Greek gods and still being the same age at the time of WW1, I think the average film goer was able to connect the dots that magical things are happening to allow these women to be immortal. Either innately or on the island.
When we get more Amazon scenes in the sequel though, I would like to see the fountain of youth. I liked the way it was drawn in the new Earth One volume. Preferably if it is firmly stated to be a gift from Aphrodite.
Theres a reason why Ruckas 'Everything Wonder Woman thought she knew was a lie' spiel made so much sense. The editorial on Wonder Woman cares so little about the book that no effort whatsoever is made to give Wonder Woman a consistent backstory. You just know if someone tried playing this fast and loose with Superman or Batman the editors would be coming down on them hard.
Ah thats what you meant. Thats a good point. I wasn't really thinking about it in regards to the movie because we still don't know if the Amazons would likewise be immortal should they leave it. We simply have no evidence one way or another.
They kind of filled in her backstory with Year One and Godwatch. The little details beyond that aren't as important, she's still the Amazon princess and she left the magical island with Steve Trevor to go live in Washington D.C and fight Ares. The important thing is that the Amazons aren't murderous anymore and that she's still a demigod, the last fact not being contradicted by Rucka, he just chose not to address it much. I think the direction is to keep some basic ideas from the New 52 era and ditch the rest, and not worry about the details lining up because that era was kind of messy to begin with, and they're not proceeding with much of it anymore anyway, so why worry about it?
As for your last point, I don't know if Superman fares much better. I think his Rebirth was much messier than Diana's and they ditched his superior New 52 origin in favor of something much more vague that owes a lot to Johns' Secret Origin. All because his costume sucked and he needed to be married to Lois, neither of which seem like issues that needed such drastic changes.
Its kind of difficult to tell when it's just Diana, isn't it? I think her being a demigod has a part to play in her being immortal, but it's not addressed. But I don't know if I consider that a total lack of world building, especially since we have another whole film coming out that is confirmed to have Amazon scenes, and maybe a third, so the whole story isn't over. Also, we're comic book fans and we are aware of the character's long and contradictory history and all want to see different things confirmed in a film, whereas the casuals don't put any thought into it at all. They can roll with Diana being immortal and not need the specifics spelled out, they don't have a horse in this race.
A shame that Robinson followed up Ruckas run by creating a plot hole thats only reconcilable if we ignore his run entirely.
Which plot hole is that? The demigod thing? Because that was never going away, the road to Rebirth set up the existence of her (stupid, awful) twin brother. Rucka hinted at his existence in Wonder Woman Rebirth #1.
Diana being a demigod doesn't create a plot hole in his run. If the patrons give her powers, that just means her demigod nature didn't make her more powerful than the other Amazons without the extra boost. Not all of Zeus's bastards are as strong as Hercules, are they? They need to spell this out more, but it's not a major source of confusion. Robinson also continued to use the supporting cast Rucka used, name dropped Etta and Sasha, and touched upon the Godwatch stuff. His run is still bad, but it didn't disrupt anything.
No?
As I explained above, it was established in Johns Justice league that Hippolyta gave birth to jason and Diana upon arriving on the island and that Grail was born at the same time. Its established that Myrina Black left the island and that Grail was supposed to be a badass because she trained for thousands of years with Myrina Black who was this proto Wonder Woman who had a trophy room from defeating the likes of Baron Blitzkrieg and such over the centuries.
Robinsons run established Hippolyta giving the immortal argonaut a baby jason in the modern day and that said dumb idiot was raised in the modern age and is at most in his thirties.
Which is significent since this determines how much of a threat Grail is expected to be, how world wise that idiot brother is supposed to be, and how well trained Wonder Woman outta be.