I don't know what exactly difficulty is for EA.
My 1 playthrough was hard smirk I struggle a lot - but on my second one I was backstabbing, hiding, king of the hill - and it was pretty easy.
Some fights were hard - but it's strictly related to lvl4 cap.

Its obvious that some mechanics will change - currently its way to easy to cheese fight by using some mechanics (like hiding).
There also will be some kind of hard /tactician difficulty.

Its to early to tell if BG3 is to easy - basically we need to wait how Larian approaches current OP mechanics - like shove.