To say this, doing some calculations from what Chip posted on Twitter; MK will be 1,74 acres in total, with DK bringing in a whopping 4.7 acres for the attraction itself.
And considering that Yoshi isn't anywhere in what's mentioned, and that SNW would clock in at 8.8 acres, subtracting that with the Acre's of both MK and DK, the land itself would have 2.36 additional acres for whatever they'd want.
It was also referred to I think by
@Disneyhead that Zelda is a frontrunner for Gate IV, so the thought of me goes is Pokemon as the obvious choice for an IOA expansion.