I visited Universal Orlando Resort just a few days ago and was fortunate to have several opportunities to speak with members of the creative team and staff. During our conversations, we discussed the future of Mythos, and they confirmed that it will remain. They also emphasized that submitting feedback for improvements is extremely important to them, and that guest opinions carry real influence not only in supporting their intentions, but also in helping make the experience better.
For example, I filed a request to fix the top layer of Volcano Bay waterfall and erupt effects that has been turned off for 2 years. Guess what, they actually listened and fixed it. And now both of effects has been fully functional.
And I also added tons and tons of more requests for improvement while I was talking with them a few days ago; they were typing and taking note of what I said.
Unlike Disney, Universal actually listens. So if you have ideas for improvements or frustration with their direction, don't just write here, write to them!
About the new expansion on the lost continent, I haven't heard about Pokémon or Zelda being utilize from them but few staff members mentioned about One Piece ip.