Yes, we can see how that would be frustrating. To clarify for other users, if you have a Certification Check of "Ham Radio Operator" and members with that field checked, then later change that field to read "Heavy Equipment Operator", the original members that had that field checked will now continue to have that field checked. The Ham Radio Operators are all now Heavy Equipment Operators. The Certification label changes, but the check mark or certification type or certification date will remain.
That necessitates manually removing all the previous information in the field you wish to change. We suggest printing the Certification Status Report on the Member record before proceeding.
We will review that feature request and update as necessary. The info couldn't clear by default as a team might just want to clarify a field's label description without losing the existing data. The mechanism would probably have to be as you suggest, allowing an administrator to clear a field over the entire team.