Tiamut’s hand is referenced in a She-Hulk Easter egg, and it looks possible more is coming of it based on the logo of the Global Community Summit in the new Captain America movie.
Multiverses are fine. We used to deal with them fairly easily before, although it was easier due to their being in different mediums. No one was confused by comics Batman, Michael Keaton Batman, and Batman: The Animated Series, for instance.
