The national media have to "anoint" players in order for them to be considered "worthy" of being an MVP. Things could change as the season progresses, but right now the only possible MVPs for the upcoming season are LeBron, Luka, Giannis, Curry, Leonard, and Harden (the latter one is only possible if he doesn't miss time due to his holdout).
Durant would normally be in the discussion but is working his way back from injury. AD is MVP-level, but he'll never win it while on the same team as LeBron, unless LeBron gets injured and AD carries the Lakers to a top seed, but neither of those things is likely to happen. Westbrook is now sharing a backcourt with Beal, which I think will take away enough stats from Westbrook to rule him out (plus, the Wizards are likely to be kinda bad).
As for Tatum, he can get there, maybe even this season, but he's gotta routinely play like he did in the playoffs, and even then he'll need the media to deem him eligible. That last part is unlikely to happen this season, IMO. But maybe next year.