Buzz would be the perfect spot. Toy Story doesn't need two shooting game rides & TSM is a lot better than Buzz.
The likes of Pirates, Haunted Mansion, Big Thunder, Everest, the original Imagination, etc... all have staying power. But so do Tower of Terror, Indiana Jones Adventure, Splash Mountain & probably Flights of Passage/Rise of the Resistance too.
Not mention that there's been plenty of original attractions that have fallen flat on their faces too; I don't think anyone's going to cry if Mission: Space gets the boot.
It's nice to have these unique, original ideas for park attractions & it's definitely an issue that the US park haven't received a new one in 17 years. But if an IP attraction is high quality then I don't think it matters all too much.
I think the real issue is that there's been a lot of recent attractions that are just "alright". There's been a heavy reliance on screens & those will never be better than physical sets/animatronics. It just so happens that these attractions are all IP based, so it's easy to compare something mid like Mickey's Runaway Railroad to Haunted Mansion & then blame the huge gap in quality on the usage of IP.