I see no reason not to change into a more particularized message using  but please understand that do so solely because I see no harm in the change and don't wish any bad feelings between us. If I had come across this user, engaged in a pattern of positive edits as you say, it would have come into question for the same reasons. Only the manner would have differed: probably a tailored message for him in the same vein as , but the username would have to go, regardless.