This is fine. A problem arises when you assume that this will always be the case, for all developers, and then mandate that they omit comments, _without checkin

This is fine. A problem arises when you assume that this will always be the case, for all developers, and then mandate that they omit comments, _without checking if your assumption is true for their case_. IMHO that rule can be generalized: Whenever you make rules for other devs, make sure that the assumptions on which those rules are based are true, lest you interfere with their work in a negative way.