I think instead of higher difficulty, it would be better to make the AI smarter.
But if they did try to make it harder, I would love them to make it Uber-hard, as in it's so hard that making Pacifist route would be better, making Char/Wis/Bard based character shine.
To be honest I don't know how they'd pull it off though, 5e isn't exactly complex that it allows enemy greater possibility to out hand your character. I think they just gonna make the enemy level higher than you a few level more.
