I don't have any information on this one way or another, and clearly both have become unique and interesting locales in comics books that are different. However, in looking into the two locations, there are several similarities.
One of which, that is prevalent is the concept of a rare metal being found in the region. With Wakanda, it is vibranium, and with Paradise Island it was Amazonium, the original metal Diana's bracelets were made from. Now, the current Wonder Woman, even the Post Crisis one, has bracelets made from the shield of Zeus, but I'm more directly talking about the original.
Looking at the two more in depth though,
Both societies are not very open or welcoming to outsiders and are constantly on the lookout for invaders.
Both societies are led by a character who is heir to the throne
Both societies view females highly as in Wakanda the Dora Milaje are the bodyguards of the Black Panther. They are often seen with swords, staffs,and spears.
Both societies are very old, and take their heritage very seriously (though everyone would do that)
Both societies seem on the surface to be archaic, but are actually very advanced (wakandan science and inventions, Paradise Island Purple healing ray, invisible jet)
Both societies have a lingering problem in that the meteorite that brought the Vibranium is also mutating people and animals, and Paradise Island has Doom's Doorway.
Both societies have an element of magic to them, with the Black Panther cult of Wakanda and the Greek pantheon of Paradise Island
Both societies were altered forever by something crashing into them (Wakanda the meteorite, and Paradise Island, Steve Trevor's jet.)
In Wakanda, they are very concerned about outsiders coming and getting some of the rare metals that are from the meteorite. If I recall correctly, one of the Lynda Carter TV show episodes, has characters invading Paradise Island in an attempt to steal the metal that makes Wonder Woman's bracelets (though that episode happened after Black Panther's first appearance).
Furthermore, when DC and Marvel combined for the Amalgram series, in Bullets and Bracelets, the series featuring Diana teaming with the Punisher, it is Black Panther who gives her the metal for her bracelets.
This last part is a bit of a stretch, but two regions of Wakanda are known as Panther Island and Paradise Forest.
Don't get me wrong, I am not saying Wakanda is a ripoff of Paradise Island or anything like that. Both of these areas have elements that are unique and very cool. I was just curious what others thought about this, and if it was anything.