I'm not saying he is, i'm only guessing, he literally knows nothing about the gay community, he looks at girls dancing on tv and switches the channel, he always talks about how cute this guy is or that guy is from movies and real life too, he's 10 years old, doesn't know anything about sex or possible relationships between same-sex couples. do straight boys also say stuff like that?? just thought it would be cool to discuss that.
He could be gay or could be very "innocent" in not knowing that its unusual for boys/guys to say that about other guys (hope that makes sense). He's also still at the age where he might think girls are "ewwww" so he'll be focusing on boys
I think ten year old kids know more than most people give them credit for. He may also be testing the waters to see how people react to his questions and comments. At his age you probably shouldn't read to far into it as proof of his sexual orientation though.