The people denying it are Gofags and Paid Shills.
It's because they're desperately trying to push Go as something good and interesting and then suddenly something like this comes out and it totally totally sinks any attention Go had.
So they're upest because the game they want to get attention is now being ignored or the fact that they're probably not going to get paid as much because people are not focusing on Go.
So they're trying to sink. That's the thing though
New Pokemon ALWAYS trump shitty spinoffs in terms of popularity. It's why the fucks at Gamefreak think hording a new evolution or form or two is enough to get certain people to buy a game like they did with USUM