talk where I work (a civil service department) of returning to potentially 2 days a week back in the office. How enforceable that is will be another story.
I can see it getting messy, especially for people who have settled in to working from home constantly and don't want that to change.
We had a 'consultation' just for our small sub-team and settled upon agreeing one day a week when we'll all be in, an additional one day a month that will be blocked out for planning/catching up and beyond that people can work wherever they want. I think it's very flexible and happy to go along with it.
Within our broader team though there are people who want to work every day at home, every day in the office and most things in-between. There is currently someone working in their second home somewhere in Snowdonia that disrupts every Teams call because their dial-up connection is hopeless - I think it's generally accepted they can't be doing their job very productively (they are an analyst so most tasks involve shunting large amounts of data from the central servers to their client laptop and back again)! It will be interesting to see what the corporate guidance is and how enforceable it is.