Single player. The developers said they used AI battles to balance the game. It would be pretty silly to balance the game around AIs that cheat wouldn't it?
Give me some links since I'm still not sure what we're talking about here.
My understanding of what you're talking about is that they run a bunch of AI matches in order to decide on how to do balancing for the movesets or frames or whatever.
(which I guess could work, but my impression is that your AI has to be godlike in order to cover most of the situations actual people do, which may not necessarily be the aim for singleplayer stuff)
Even if they did do this, this doesn't necessarily mean that the modifier for difficulty won't end up being something stupid like input reading.
But then it's also possible that they'll keep it "honest" and you just steamroll on all difficulties once you learn to punish during a specific situation the AI feeds you, which I would kinda prefer even if it's an easier experience, putting myself in the shoes of someone that maybe doesn't want to play to competitively.
(but then I do actually wanna compete, so the singleplayer stuff isn't too relevant for me... but the least game makers can do is not make it miserable for the players that want engage in this part of the game)
High level CPUs in Smash Bros. for Wii U/3DS are an absolute nightmare to fight against, lmao.
They literally input read and dodge every, single, fucking, attack. Playing 9.0 in that game made me want to pull my hair out.
Let's let the AI punish you for some random shit that no normal human can react to consistently.
Great design :v
(but yeah, you normally have to just exploit this after a point in order to win, but that ends up being kinda unfun)