As a POD.
If instead of gay flight attendants...
How about promiscuous male straight airline pilots? Or even whoremongering pilots?
If you like that POD, make some city in the Congo/Haiti as the Bangkok of Africa/Haiti. Probably need to use Airline Pilots. If I was writing the POD, i think I would go with something like this.
In Kinshasha (or your favorite city in the area), there are a small group of high end brothels (3) that have a small number of workers (under 1000, maybe well over). Aids arrives as OTL, mostly by following truck routes. A small group of pilots (under 15 frequent these joints) and bring it back to the Americas. After all, how many pilots fly the USA to Congo route on a regular basis? You bring it back to some hub city in USA where these pilots also use a lot of prostitutes, go to a lot of wild parties, and do IV drugs. It gets spread around the city, then it is either the "Miami hooker" disease or the "Pilot" disease.
Or it you want it to be less obvious where it came from, these pilots spread it in some tourist city outside of USA with lesser health care, say Bahamas, and it is less clear how it makes it to Miami.
Or you just have the POD with no gay stewardesses, and it simply comes over to the USA from Haiti sometime in the 1980's, maybe early 1990's, probably with immigrants moving back and forth. It was not destined to be know as a gay disease, and a no time after 1960 were the majority of the victims primarily gay in sexual activity. We just did not know about the larger number of Haitians or much larger number of Africans who got it through more vanilla hetero sex.
Also, it is key that it was the third case in a few months that got the doctor to all the work that lead to CDC doing the work. Once is an accident, twice is a coincidence, three times is a conspiracy. Once case of the skin cancer is "O well, some guy/gal has a bad immune system". Two will likely be "It is just bad luck, odd event" Three triggers work. So it could have been any group that had the cases. It could have been 3 rich white women in their 30's from good Ivy league families that slept with some playboy bi-sexual (mostly straight sex) college girls in Boston, and be the "Harvard" disease. It could have been some flight attendant in Atlanta and be the "colored disease" or "slum disease".
Hell, if the three guys seeking original treatment had just moved around the country, and it was one guy in San Fran, one in Dallas, one in Boston; it is likely years later we figure out what is going on. AIDS could have been the full black death, with some minor POD including not picking it up earlier or minor changes to infectionous nature.
I would argue that AIDS for many parts of Africa is as devastating as the Black Death was for Europe.