I think it would cause some outrage if this version of Drake all of a sudden came out to Sully, Elena or something, but if the series was rebooted in the future there's no reason why you can't have a gay Drake, you just need to develop the character right and deal with this element of his personality/lifestyle right.
IMO it would make a lot more sense to make a new game, with a homosexual protagonist, or maybe that stuff shouldn't be so important, the character is just a means to take you on a journey, through a fantasy world. I'm not saying don't deal with important parts of the character's story, but only mention sexuality and other parts of the character's identity if the story leads to that. Like if a girl comes on to Drake in a bar that he's looking for info in and he fobs her off or just comes straight out and says "I'm into guys sorry".
Uncharted could always have a new lead character if something happens to Drake and they could be gay. Maybe Naughty Dog should introduce someone.
Personally I hope the series carries on for a long time and anything can happen.
Provided the introduction of a new character feels natural I wouldn't mind if they they were whatever sexuality fits for their persona, it just has to work well as far as they're concerned IMO.
