Dr. Strange seems to be okay since he appeared as a M&G. Other than that (and GotG), I think it's up to debate. I don't think any of the upcoming movie folks would fit (Ant-Man and Captain Marvel seem to connected to established Uni characters to be possible).
On the TV side, there's options maybe. The characters from the Netflix shows could be a possibility, but given the more mature content from those shows, I think they would be avoided or at least toned down to more child friendly representations. I've often wondered if a SHIELD based attraction would be okay. They have TV shows planned based on the Inhumans, Runaways, Cloak & Dagger, and Squirrel Girl/New Warriors -- all of which could arguably be possible (or not) depending on how one interprets the contract with Uni.
It also depends on what, if any, modification or "clarifications" have happened to the contract. There's at least been rumors that Disney and Uni have come to some further agreements regarding the Marvel deal which may have helped to free up some characters for Disney to use (or at least confirm that they are available for use).