AAA = Big Budget, Big Production Values (Mostly visuals) and finally scope.
A game with fancy graphics like Hellblade will never be AAA because its scope is that of an indie game. It's a B game at best. Same goes for most Platinum games like Vanquish, Astral Chain and Nier.
I would say Gears 4, Halo 5, and Gears 5 are the only true AAA games released by MS first party this gen. State of Decay, Sea of Thieves and Crackdown fall short in different ways. All B games imo. Lacking in one way or another. Sunset Overdrive, Ryse, Titanfall 1, and Scalebound if it ever came out, are what I consider AAA games. I used to think that AAA meant great reception by critics but I dont agree anymore. Anthem has a rating of 55 on metacritic, Ryse is at 60, order is at 59. I think they are all AAA to me. Just poorly received.
Is outriders an AAA game? Hard to say from what I played. it definitely has the scope and the budget, but it looks very mediocre. I would say its an AA game but i wouldnt get upset over other claiming its AAA either. Souls games, Borderlands, and fallout/skyrim etc. dont have great facial animations or cutscene quality, and yet they are all considered AAA. So why not.
It's still at the lower end of AAA. I dont think anyone is putting it up there with Gears, FF7, Destiny and the last of us. Hell, no one even heard about it before the DF comparisons.