Many companies are announcing it but I don't see a large trend of announcements yet. There will be a growing niche, and maybe the large wave is yet to come, but for now, we haven't reached that state yet you describe.

No. I expect it to be more organic and under the radar. Some percentage of employers and some percentage of employees at those employers. And now you come into the office and only a third of your team is in there on a given day and, at some point, you're "Hey. Is it really worth commuting in for the snacks." And maybe you decide to all come in on a given day. But a couple people move a few hours away...

My point is that norms can shift without big company announcements so long as companies don't actively prevent them.

I do think this is going to become a big deal for people as they consider current and future jobs. It's probably also going to be a big issue for onboarding junior people.