I’ve been here 12 years. In that time, I’ve only seen people moderated for discussing moderation if they persisted or had also violated another rule. I’m sure of it.
I’m not going to do an exhaustive search. But I can look for all mentions of “ATMB” by a mod made outside of ATMB itself.
The first relevant results I found was this one:
That was to Paul_in_Saudi, who is not a new poster.
Here’s the relevant part of another post:
mordecaiM is not a new poster.
This was apparently to Mallard, who is not a new poster (been here since 2013).
These were the top three I found. Not a single one gives out a Warning. It seems your memory on this is faulty.
Note: do to how search is set up, I found it easier to pick a mod and a forum. So I chose @What_Exit, since his claim was specifically that he usually gave Warnings. I then looked at GD first, then IMHO. These were the top results that actually were relevant.