Are they dumping TETR for a restaurant? Because they can't do that. It's a classic and the first attraction with Audio-Animatronics. I hope they never do.
Where did you hear that one? Personally I think TETR could use a good refurbishing, some of those AAs look pretty beat, but I'd be bummed to see it gone. Aladdin's Oasis is gone now and that space was the Tahitian Terrace Restaurant before that. Maybe they're putting one back in there.
Why would they do that? They just spent millions to totally rebuild the building and restore the whole thing to its original condition. Heck it has higher numbers than Winnie the Pooh.
They could still do a bit of fine tuning on the ETR. Some of the AAs don't seem to be working quite right. Little stuff, Tikis that don't function as designed. Orchids that should be signing but didn't. All minor complaints.
Tiki Room isn't going away. However, it may get a holiday version or an updated general show (Overlay - Perhaps stitch related) at some point in the future. All of that has been kicked around at one point or another in recent history. Attractions usually get the overlay/makeover treatment if their numbers start to fall, so if you don't want to see the Tiki Room change, you should make it part of your regular park experience. Otherwise, you really can't blame Disney if they end up making changes which they hope will boost attendance.