To expand on my answer, I think that it is a great idea for the future, or for a group of profiles that are more "mature" in their state of completion. I'm not saying it shoudn't be implemented now, but I might not be ready to use them with the profiles on my watch list until a significant number of them start approaching a higher level of completeness. Until then, adding a maintenace tag is just adding extra noise to the profiles.
Now, the more I think about it, perhaps replacing some of the default text for new profiles with a "this is a stub" tag might be a good idea.