You have a point. I did not see it on their PA in Fallout 2
To be fair, though, the only part of the suit we saw in any great detail in FO2 was the head and shoulders. We certainly wouldn't have seen any logo or anything on the sprite.
If they are people that used to be in the Enclave they should have marked out the logo.
Why? Just because they're not necessarily part of the Enclave any more doesn't mean they don't have pride in its symbology.
If the Enclave is back then why did the Enclave use that crap PA in FO3?
In theory, the crap devilsuit in FO3 was what "Advanced Power Armor Mark II" always looked like, with the FO2 style suit being the "Advanced Power Armor (Mark I)."
The stats were totally messed up though since the suit was significantly inferior to the T-51b. Obviously the FO3 stats were incorrect.