I don't know exact issue, but it was Fraction's run that a lot of this stuff got added in. He made a lot of tweaks to things, Frigga to Freyja, that a child of her and Odin is the true heir, it all comes from his run. I know his run wasn't the greatest, but... it is canon.
Balder is still Odin and Freyja's son, it's just that since they were not yet married, he loses out on a technicality. (I think, basically, Fraction really wanted the whole Aesir/Vanir prophecy baby thing, so came up with an excuse why Balder did not count... and then Aaron promptly ignored Freyja being pregnant, and left it to Gillen to wrap it up in Angela anyway.
) And he and Tyr are both dead right now, anyway. It seemed like maybe Balder had been brought back, but he's in Hel with Tyr in Angela's book right now. I think the broad strokes of all the siblings origins remain the same, but the order in which they were born is always being changed. A couple of them (Hermod and Vidar) have not been mentioned in many years, just... completely ignored recently, as if they had never existed. They may be dead, they may just have ran off and chosen to ignore their screwed up family, they may no longer be canon, I dunno, they just fell off the table at some point. The only mention of them I know of recently was Hermod being a contact on Loki's phone, but that was just an easteregg type thing.
Eh, we already know he will end up king one day anyway. Not under the best of circumstances, true, but....
All of Odin's children are still heirs to the throne. They are all still princes/princesses. They just can't all be first in line. All it will take is for Angela to be bumped off at some point, or to have Aaron make some changes to the rules of ascension in the story because everyone realizes it would be a really BAD IDEA to let Angela rule due to her being raised as an angel, just like the Frost giants would never accept Loki ruling them even if he IS the biological son of their king and technically is Laufey's heir. But he's spent so much time in Asgard at this point that while he may boilogically be a frost giant, he has virtually nothing in common with them, he's even changed his appearance, and is for all intents and purposes an Asgardian at this point. It's the same deal with Angela, except it's the Angels who raised her. The difference is that Laufey is a complete dick and has no qualms about killing Loki to simplify the situation. Something I don't think Odin would do with Angela, even in his current state of mind. Aaron did co-write the 10th Realm series where Angela was revealed to be Odin's daughter, so he must have realized what it would mean, and then bringing back Laufey... I think he's clearly going to be diving into the whole issue of whether it's who raised you or who birthed you that is important.