Any AI features, helpful or no, seems to me like something that should exist in the form of an extension, not baked into the browser. Or, if baked in, should be opt in, not opt out by default, as regardless of where you fall on it, AI is a divisive topic and people have strong opinions on it. Especially the people in Firefoxes remaining small audience that tend to be more technically literate and privacy/security conscious.
I have no problem with it announcing new features and asking if I wish to enable them after an update, but I'd really rather prefer it not to force enable new features (regardless of proximity/relevance to AI) whether it tells me about them up front - and especially don't want it to if they aren't even notifying me of it.