I think that more and more, sexual orientation and gender constructs as binaries need to be broken down, unpacked, and dismantled.
Both are a spectrum. If you're attracted to someone, you're attracted to someone. What you do with each other is all up to the people doing it.
Im sure there are plenty of guys who consider themselves gay because they like dick. Dick in their mouth, dick in their ass, etc... maybe the other partner's gender doesn't play into that as long as they have one. Boom that opens the door to all sorts of combinations and possibilities.
Same as how some gay guys like other guys, but if the other guy happens to own a vagina, and that's up for being part of the sex they have, then great.
The thing about sex and gender is that there's no wrong way to do it, so even though there are people who are really into the conventional categories for things, there are just as many who don't really care, or don't see it that way. There's no right and wrong way to do it, and those parameters only really matter to the people who do it, and how they want that to come into play with who / how they fuck.