It still won't be a big bang moment. There might be a moment you can go hands off on highways, and a moment you can go hands off in urban environments. But it's still going to be gradual overall.
My understanding is that Tesla's approach is to not require hyper-detailed maps. So far it doesn't work well enough, but if they do manage to get it working, then I think it will actually be a "boom, suddenly it works everywhere" moment. Waymo One, by contrast, requires extremely detailed maps of the service area, which is why they can only slowly roll it out place by place.
I've been a bit surprised that no one (well GM was mildly pushing in this direction at one point) has really gone after autonomous driving on selected highways within some weather parameters. I know urbanites get all worked up about robotaxis but a system that lets me chill for the next 100 miles of highway driving seems far more interesting if it's reliable/safe.
