I recall that my son’s kindergarten (brmck) had a shared bathroom (no shower facilities) for the kids. The sinks were clustered at the centre of the bathroom, easier for the teachers to eyeball their washing of hands.
The cubicles all have lockable doors for privacy. The girls were told to use one row of cubicles at the left side of the sinks, the boys used another row of cubicles at the right side of the sinks. No urinals.
I believe that’s private enough.
Have you seen some preschools that lack sufficient privacy? Do share!