Ubersampling might be something that is not too difficult to implement, so it would not be unrealistic to expect it to appear in the GOTY edition. On the other hand, it is also something that is only of interest to players with high end PCs, and it is already possible to achieve a similar effect with DSR or VSR. But if it is easy enough to add, then why not, except maybe to avoid complaints about bad performance at maximum settings.
Technically part of it is in the engine, it fully supports separate render resolution with upscaling to match the viewport (hello consoles) but not other way around.