It actually were multiple problems and given they only really appear on multiplayer servers, QA was having a hard time to check them, as hotfixes only get PR testing due to going out asap. We have no way to test such changes on multiplayer servers outside of playtests for minor and major versions.
At first, the problem reported was that any change, no matter how small, did give a notification - which was addressed by requiring a more notable change. Then we noticed that culture going down (which was brought to our attention by admins, happens very frequently on servers due to room changes invalidating cultural objects for short moments) also causes them. So it was changed to not put out notifications when it goes lower and only when it reaches a new threshold. Now there is the problem you mention (that gets more severe the more active the server is), but there is also a problem of sending a notification when nothing changes at all in regular intervals that is the only one that can be observed in local testing. 10.1.3 should tackle it completely.