“For agencies supporting many sites, whose users have no way of knowing whether Gutenberg will break their site or not, this nag screen is a danger,” Schoppe commented on our most recent Gutenberg update. “Pre-emptively installing Classic Editor unfortunately won’t suppress the nag notice either, but since Classic Editor is being used as a bellwether of the success of Gutenberg, it’s important that you install it, if you expect issues.”
I am definitely going to have to consider this, and hosting WordPress remains a struggle between letting site ops run amok install as they please, or keep a site locked down so members have to hold a hand to get anything done…
Of course, one way to mitigate these kinds of decisions is to completely decouple the editor experience from the WP codebase, maybe with a custom WordPress editor.