I’m afraid I can but speculate.
Meth is certainly a party drug of choice among gay men right now in some subcultures. It’s my general but non-data-supported impression, though, that meth among gay men as a party drug or sex enhancer is quite a white, middle-class phenomenon.
I don’t think that elevated HIV prevalence rates among young, gay black men is particularly well correlated to drug use. It doesn’t seem to be in Detroit among young gay black men I know personally.
But please take my observations with several grains of salt. They’re limited in scope, and I have nothing to back them up with.