Compared to fan expectations, probably Fallout 76. Fallout 4 + Bethesda + debut online multiplayer effort sounds like a recipe for a clusterfuck.
Battlefield V has already suffered most of its backlash - hard to see how fans can get any more pissed off, unless it's also full of bugs and has online launch issues. Same story with BO4 and the dropping of single player.
I think for Pokemon, fans have tempered their expectations already and will be able to enjoy it for what it is.