Is this actually confirmed? I can't see the park moving all the animals in the Trail of the Kings area (albeit there's not a lot left there) to a different part of the park. I wonder if the Gorillas will go to another collection.
Not confirmed for all animals.
However, i's certainly my understanding from the recent planning applications.
Here is an excerpt from the Scorpion Express replacement application:
This makes it clear the animals from the Petting Zoo will go to Wanyama. It certainly suggests that all animals will head that way too (after all, the petting zoo doesn't have animals which require enclosures better resembling natural continental enclosures).
On top of that, in the Wild Asia replacement application, the park highlighted they considered replacing the Trail of the Kings with Minecraft World:
So the park have actively considered removal of long-standing parts of the Zoo. And it certainly seems like they're reversing recent years of Zoo and theme park integration, and planning to put the zoo in one area.
From a purely speculative point, I wonder if the park will look at removing the costly and not-so-popular Zufari, and extending the walkable part of the zoo/Wanyama around there. They can't build rides on that area, but can in areas like Trail of the Kings. Moving all the zoo to one area might help the theme park expansion and long term development and sustainability of the resort as a whole.