This is an interesting example of the Clever Hans Phenomenon. You think you're comparing GPT and Google equally but you're actually giving GPT much more manual help. A search as simple as "UUG acronym" gives me the answer in a box at the top: "Unix Users Group" (tested in incognito).
GPT is useful, but there's an annoying tendency of it's proponents to promote it with examples they haven't validated.
Interesting. The same search term returns "UUG is an acronym for: Uniface Users Group. Universal Underwriters Group." in the top box for me. Also in incognito.
This user group was already in place by the time Linux came along, so you had the UUG doing Red Hat boxed set giveaways and such. There was a ton of excitement about Linux and not as much about Unix at that point. Then a bit more proper-Unix excitement when OS X came out.
I got my uni CS club going on IRC. I’ve recently discovered that they’re now on Discord. I get it, like, IRC is increasingly undesirable these days, especially without a bouncer. It still hurt though.
The other guesses were: CDE - Common Desktop Environment, MTC - Missionary Training Center.
GPT is much better than web search for this, I'll say that. It's ability to use context is invaluable.