I am unaware of reports of such assaults on homosexuals in bathrooms.
Perhaps they are a result of “rough trade” responding to an unwelcome sexual proposition in a restroom?
It's more likely that normal people are accosted when restrooms become cruising spots for homosexuals preying on normal people. I can remember certain highway rest stops that people were advised not to use because you would be propositioned, or worse (happened to me once because I had the gall to actually rest in my car during a long trip.) A certain men's room in a department store where I worked during college became such a problem with homosexual propositioning and sexually touching normal men going about their business that undercover police had to be deployed to stop the disgusting plague.