That is true... some gay people are no better than heterosexual people in discriminating and rejecting transgender people, but they usually will not assault or harm you.
That is one of the few reasons I prefer going to gay bars/clubs than straight ones, because I do not have to worry about potential assault if a straight man hits on me and finds out that I am transgender., especially if he is drunk.
However, I have had few pretty wild one-night stands from straight bars, but I consider myself very fortunate that they did not harm me when I revealed my "->-bleeped-<- surprise".