Back in 2021
@AlexanderMBush proposed a revamp to the lower lot that involved tearing down the mummy and the soundstages above it for a Production central like area that could lead into mini lands if Universal wanted and would allow them a place to put a new studio tram if they decide to use the current tram stop on the upper lot for theme park expansion maybe lumping in the Simpsons Ride replacement into this new land.
But one proposal Alexander mentioned that may have to change is having a JW roller coaster in half of Mummy's plot and have it go over the hill since that is what the F&F coaster on the upper lot is doing, Because of that maybe Mummy's plot could be used for a large scale dark ride. If they could find a way to make that section a mini land, I would want to see that part themed to the Classic Monsters will exclusive rides to USH since it's possible that UOR uses the IOA model for EU and wants to keep the lands (sans Nintendo) exclusive to EU.
What I would want to see them do is a trackless ride around the Monsters will MK like set pieces blended with projection mapped media in the set pieces Transformers style. And one benefit that OrangeGrove55 mentioned on his YT channel about California is the state has the blessing of depth unlike Florida. They can make this trackless ride go 3 to 4 stories under ground thus making it almost on par with the current building but in a smaller footprint which could free up space for another attraction to make it a mini land.
And the second attraction would use the stacked dark ride and interactive wand patent to make a unique monsters style Midway Mania style attraction to round out this mini land.