What's the point calling it Madara, if it's really Obito, at this point everyone, or at least those who watch anime, already know this. It's not really a spoiler since this game has no story as such anyway, so those who do not watch and plan to watch, wont even realize until they hit that part, but hey wont know anything about Obito or Madara for a long time.

The only Madaras we have are Six Path, Edo (if there will be such), and Konoha Founder edition. The rest is Obito full time.