If the JW dark ride does make its way to Hollywood, I would not mind if this replaces Mummy. Since it would be literally right next to Transformers, I wonder if this would make that ride obsolete? It's literally Transformers but without 3D, more AAs and practical, and most likely more aggressive/thrilling.
I don't think we'll know till the ride is open. Irrespective of whether it makes Transformers obsolete or if it could even fit in the Mummy showbuilding, I would still prefer a more fleshed out Jurassic World area with something replacing the Mummy. My main hesitation is that the dark ride's structure adheres too closely to the structure of JW in Hollywood. Both involve an escaped Indominus Rex. If you place both rides together, you have two rides telling the same story, which necessitates a drastic rework of either the River Adventure or the dark ride. Additionally, it seems like the Beijing Dark Ride and the Jurassic World River Adventure might share some of the same animatronics, further complicating this idea.
With the LA Olympics and the eventual construction of additional high-tech soundstages on Falls Lake, I'm certain something's destined for that space. But if it's a Jurassic ride, it will have to be (cough*) drastically different from its neighbor across the street.
EDIT: This probably belongs on the Hollywood forums, and if this elicits further discussion I'll bring it there, but I still think there's work left on the upper lot. The Walking Dead and Special Effects stage buildings are ripe locations for expansion, and they could rearrange CityWalk to push out the entrance and free up more space.
EDIT 2: Oh, and they'll have to figure out what to do with the Simpsons.