But the rules don't say that a thread can't be bumped unless significant changes have been made to it.
There have been no recent changes to the bump rules, so I doubt this is the case, bumps can be made without any change at all to the OP, I for one bump my service thread like that.
This case could be a mod misinterpreting the situation, it's rare for that to happen more than 4 or 5 times, but it is possible. Maybe the mod who took the action could respond here with the reason.