The case for Ghost Busters at Universal Orlando:
1) Ghost Busters is currently an untapped IP with a lot of recognition and viability for a theme park attraction.
2) Ghost Busters fits perfectly at Universal, specifically in NYC. The IP likely couldn't carry an entire world, just an attraction at an existing land.
The case for replacing The Mummy:
1) The current movies which Revenge of The Mummy is based on are not relevant. And Brendan Fraser is no longer relevant.
2) The ending scene is flat out awkward, because many people don't even see the extended queue videos with Brendan Fraser. Many people end up straight in the 'spooky artifacts' room, and the only time they see Brendan is at the end of the ride. This leaves people confused as to why we're seeing Brendan at all and why he's screaming about a cup of coffee.
3) Note that Brendan is actually playing himself, he's not playing his character from the movie. This is a relic of Universal Studios' old premise that you 'ride the movies,' with a strong emphasises on showing you, the park visitor, a behind the scenes look at the movies. However, since Mummy had been added in Orlando in 2004, Universal has replaced Jaws, Disaster/Earthquake, and Twister, which all shared this premise, with a new focus on rides like Transformers, Despicable Me, F&F, and Gringotts, which ignore this premise. Mummy's premise no longer fits in. (There's still a few others which hold this premise but mostly it's on its way out.)
4) The Mummy IP would fit better at UFW if they add Classic Monsters.
Due to the above six reasons, I'd love to see a full refurbishment (not replacement) of the ride, rebranding it to Ghost Busters, with spooky ghost theme, new animatronics, cgi animation, pre-show with original cast, and other updates.
Refurbishment with new IP would allow Universal to do this on the cheap with also being able to advertise it as a new ride (as they have with other refurbs, including Simpsons and DM).
That all being said, the ride itself is really fun and one that I try to go on often during my visits (probably been on it about a hundred times).