I really think this varies by consoles now. Nintendo's games can't be AAA compared to Xbox One and PS4. Completely different platforms with different specs and time needed to fully develop a new game. I remember an article talking about how in the 7th gen it costed around $20m for a game on the PS360, and around 2- 5m for the Wii. Right now I'd assume $80-100m for a new game on PS4/Xbox based on what Remedy said, and Square Enix announcing the new Tomb Raider costing a solid $100m; and 20-30m on the Switch for a game built from scratch.
Nintendo can be low budget compared to Microsoft and Sony and still be AAA because of the Switch's situation. For them it just comes down to the scope of their game and the marketing budget, Arms, Mariokart, and Splatoon would not be AAA, they are small games that look dirt cheap to make. BOTW and Mario Odyssey would definitely be AAA.
Microsoft and Sony seem to be more realistic and upfront with what games are AAA and what games are not. Albeit Microsoft only fucked up with pricing Sea of Thieves.
If Nintendo published Cuphead, State of Decay 2, and Ori; they would all cost $80(CAD) and people would call those games AAA, like they do for majority of their titles.