Its strange that you choose to focus specifically on the sexual behavior as the defining characteristic. The attraction to the same sex might be the defining characteristic of the group, but it is not the defining characteristic of any individual. And that is the entire point. I doubt any of the people hoping for another athlete to emerge wants that athlete to detail, promote or otherwise advertise a specific sexual behavior or practice.
Just as Jordy Nelson's ad with his wife is not meant to be a testimony for heterosexual behavior, the appearance of a active, out professional athlete is not meant to be an advertisement for homosexual behavior.
I would hope that any person who chooses to do this does not do it to fulfill a sociopolitical movement. I hope they do it so the appearance of the object of their affection in Wisconsin Tourism ad, at a game, or in an interview is as run of the mill and unremarkable as the appearance of Mrs. Nelson in the ad.