Releasing an entirely new, and almost entirely different editor in WordPress is A Big Deal, but I personally don’t care that much.
I edit using so many different editors, on web and desktop and mobile, that I’ve learned to deal with whatever’s there and be done with it. As long as one of my favorite choices isn’t readily available, that is.
It’ll be interesting to see what happens in six months once we’ve weeded out all of the “OMG! It’s too different, change it back!” reactions and people have settled down. At least I assume they’ll settle down, but ¯_(ツ)_/¯.