This is an accepted, if not encouraged, practice at my employer and it is much appreciated. Entire teams tend to schedule their "WFH" days together as a general time to focus, no meetings, etc. And, the teams that don't schedule together almost always have most members taking 1-2 WFH days a week.

For context: Employer is a late stage startup with ~500 employees that generally embraces remote work with many full-time remote employees.