I see them leaving it as-is. Even if they do a major refurb on Everest, I think the Yeti will, at best, be cleaned up (skin taken off and maybe the bits that have wear that help with his limited movement refurbished). I don't see them ever fixing it. When it was part of the new ride and a major show piece in the ride it was important. Now that it's just "there" and people are going to ride the ride regardless there's no will to fix it and certainly no budget to fix it. People are going to fly by it on the coaster either way so, in their financial minds, it doesn't make sense to rip part of the mountain open so that they can remove it, remove any track that's in the way, remove the Yeti, break apart the foundation it sits on, and then re-pour it. I just don't see that ever happening.
Cleaning up the Yeti, sure.