Thinking hard about this quote:
"Many people, meeting Aziraphale for the first time, formed three impressions: That he was English, that he was intelligent, and that he was gayer than a tree full of monkeys on nitrous oxide. Two of these were wrong: Heaven is not in England, ... and angels are sexless unless they really want to make an effort."
Key context is this came out in 1990. "Sexless", technically and with today's modern terminology, would probably mean either celibate or without genitalia. Neither of which present a counter to gay, so I've tended to interpret this as asexual or agender (or both which tbh is where I lean).
Obviously you can still be gay and asexual or gay and agender but that's like, advanced physics and we're talking cis men writing this in the 90s. But idk this is part of my justification for seeing A/C as a queer-platonic pairing only.
My suspicion is that they meant both genital-less and agender as one combined thing that also implies celibacy, because there's multiple other parts in the book where it specifically talks about angels being incorporeal. No body? No sex. No sex? No gay (because it's the early 90s and sexuality is what you do or something).