It's more than likely the op to that was confused not his fault as digital believe it or not is new to most of NM.
You are correct I believe his radios aren't capable. Not his fault. Digital is new for NM and the protocols for the varieties.
As for the others I cannot add with the information I know directly due to non disclosure there is A LOT of new stuff out there barely coming online in NM specially in southern NM not in the DB. From Hobbs to Lordsburg all the way up to Clovis. Some having delayed until recent.
Yes unfortunately E is in a lot places that is popping up or will depending where, and what is going on. This includes fire, public works, police, dog catcher.
Most was accurate until recent this year but keep in mind the old analog can be used as fallback still in most places and is maintained (for now) so that one is a tough one with RR polices from what I've seen as far as deprecated to in use.
As most know who are in NM holding onto existing things seems to be a common thing in rural NM even if new is being used.