But positive feedback will get affected though right? Because it is not possible to trust give positive feedback without knowing that person in deep.
I too agree that some sort of moderation needed when a person in DT network not anymore but theymos already mentioned he is not going to trust anyone.
Therefore, I think manually replace negative feedbacks to neutral ones are good solution for those rare cases.
Remove original feedbacks sounds shady, somehow. A user who had scam accusations / neg tags in the past might potentially do this again; so neutral feedback as slight warning is enough, I think. They don't deserve neg tags if their cases solved, but a pure profile page sounds unfair, somehow.
Negative feedbacks that already solved and confirmed by 'victims' or someone who tagged negatively, or well massively confirmed by community