I guess, you are implying a case of AC-21 with a new employer. Subject to the conditions as set in AC-21, if 180 days have elapsed with your I-485 pending, there should not be a NOID or denial for that. However, a NOID or denial is certainly possible, if your I-485 petition lacked form and substance in its initial submission. USCIS' logic is that if the petition is blatantly lacking any required evidence/documentation, then a NOID or denial can be issued in lieu of a RFE to save time and resources to the Service.
Believe me, INS is not trigger-happy to deny any of (y)our petitions unless there is a clear case. There was a rationale even for the denial of longGc's case which was an exception and came at a time when there wasn't a clear memo clarifying AC-21. So, as PrinceOfJungle said, just don't bother about the dysphemism and go ahead with your responses to USCIS.
This is a country of Justice and there are appellate institutions against which INS has to justify any denials whatsoever. It is amazing that they have even given up on one-time DUI cases, clearly showing that their decisions are increasingly scrutinized by the Circuit Courts of Appeals. I would still exhort people to kindly stay away from all occasions of mischief and if you know that you are not having any brush with the legal system of this country and are in status all long, then just don't worry about the verbiage of the notices you receive. Respond to those notices and that's it. Take their threats with a pinch of salt.