Just speculating but I would guess that's a reason for asking people back in the office. If you're getting paid the same amount as an engineer in the Bay Area but living South Dakota, I'm sure this causes some alarm for the company. We can't force a pay cut but what if we require physical presence a few times a week.

I'm still living in the Bay Area due to family but that's one of the reasons why we haven't looked seriously about moving. I felt like the WFH train was going to stop eventually.