I feel like Super Nintendo World getting 20 acres right off the bat seems a bit... ridiculous, even for a property like Nintendo. In this theoretical situation where we DO lose MIB, E.T., and KidZone, all around the same time, all for Nintendo, that's a closure of two lands, three rides, and several shows/playgrounds. It'd be an absolute ops nightmare, even if it's after MOM and SLOP are open. Two of those rides are fairly high rated and popular attractions that utilize physical sets, which Uni KNOWS is something the park is still pretty dry on. And then after that, that's the construction of at LEAST five rides, all at once, including Mario Kart, Yoshi, and DK in the original KidZone plot, at least one ride where E.T. is, and at least one where MIB is. And whatever is replacing E.T. and MIB would need to be at LEAST d-tickets, if not much more, to justify replacing these attractions.
So if they were to do this, they'd need to be building a 20-acre multi-level immersive land, five attractions all in the E-D ticket range, all at once, co-currently with other potential major projects that are still in the works such as the LC replacement and the South Property. Honestly? The whole thing just doesn't add up. I think, at most, E.T. will close sooner than we expect for more Mario right off the bat, or MIB will close for Pokemon right off the bat. But it won't be both at the same time. At most, I'd expect one closure to be for "Phase 1.25," and one for an actual "Phase 2" a bit later down the line.