I'm with Janelle on this one. I do agree that there should be consultation before changing dates, relationships, or whatever, because I have had people confuse people in my watchlist with other people who happened to have the same name, but had different parents, spouses, children, birthdates, birthplaces, and so on. But if I'm adding (or completing) a source for a fact which is already listed on that profile, I really don't see the point in asking permission first.
(Okay, yes, granted, it would be more collaborative to discuss things first, but I've had so many times when I've tried to contact a profile manager and never heard back because that profile manager hasn't been on WikiTree for years that now, I just make the fix and move on.)