It looks like that for Osaka; they are doing it on the front side of the park. what bothers me, is the size of acreage.
It looks excluding Space Fantasy that it's 6 acres of land, which that would fit. But; if you remove Space Fantasy, that gives you about eight acres of land.
Include the 4D theatre aswell; and you have 9 acres of land, so its not like that USJ is going to has possible problem with space on all three of these scenarios.
I'm going to assume, that the 6 Acres of land I mentioned is indeed the case; as looking over on GE (Google Earth); that lines up with Kidzones size, including ETs extended line of 6 acres. My question is; will they include the building of Space Fantasy and add a extra attraction, just for Japan to make it an incentive to go there as a exclusive.