When I was younger a girlfriend of mine used to daydream about George Michael all the time. That he'd spot her at a concert and it would be love at first sight and they'd get married and live happily ever after. She was gutted when he came out because that made all her silly dreams and fairy castles come tumbling down.
So I only think it could matter in that sense - If she'd known she wouldn't have wasted her precious teenage daydreaming time and could have had a pash on someone else.
But no I don't really think it matters at all. I don't care personally.
It doesn't matter, if someone is gay or not, it is just inresting to know. Like it is intresting to know who the footballers are dating or what an actor is getting up to. It is not the fact that they are gay, its just its something to know about them.