Comment by SoftTalker

I never tried it with FaceID specifically, but all the other red bubbles I've encountered behaved the same way: You say "not now" during the initial setup, then you get a nag/reminder in the settings app. If you tap on the reminder and say "not now" or "don't use feature XYZ" or whatever again, it goes away permanently.

Annoying - familiar with the workaround? (disabling the badge, or you need it in case a software update ships?)