Greg Louganis Is Black?

The Guardian recently ran the kind of story I hate--in which it is asserted matter-of-factly upon no evidence whatsoever that everyone you ever heard of was homosexual. I'm not going to link to it so as not to be personally responsible for spreading gossip, but I raise my eyebrows at this assertion leveled against a Black History Month resource:
The website fails to identify the vast majority of black public and historical figures who are LGBT.
The "vast majority" of prominent blacks are gay?

And may I just add the only truly surprising revelations in the column were that Greg Louganis is black. And that Great Britain has black history month.