You can already do that now. Need maintenance is an attribute so set that the attribute is required and it will filter for cache in need of maintenance.
If i am not mistaken there is also a need Needs Maintainance flag for a cache because i have seen reviewer logs complaining that the cache owner has only edit the attributes and not logged "Owner Maintenance" but to the best of my knowledge that data is not exposed in the API and cant be used on pgc.