Let me first point out a few things about openly confirmed canon bi Dean and/or canon Destiel, just to establish a baseline of where things are regarding canon.
Canon Destiel (and bi Dean) would subvert expectations on what a hero looks like.
And, frankly, subvert expectations on what queerfolk look like. Let’s look at Hugo Ateo, who played one of the famous Hunter Husbands narrative mirrors in SPN, and when he posted on National Coming Out Day.
He was already “out” among his peers but realized he never publicized it, so posted in support of others, and had this discussion about media representation – and about how he, a gay man, was never allowed to play a gay man until then because he wasn’t “believably gay.”
Pairings LIKE the Hunter Husbands need to happen more regularly, but not just as one-offs, not just as dismissive things never spoken of again. People shouldn’t go “well you had one good example in 300 episodes so shut up and sit down.” That isn’t how that works.
Destiel fits the same mold, and ironically, that very episode highlights it perfectly. It’s one of the best things I can think of to even make this kind of example while simultaneously even going so far as to address issues like repression, or internal struggle, confusion, or late coming-out or self-awareness/acceptance.
The ability that Destiel HOLDS in this corner is unlike any other I’ve witnessed.
I will also add that shows with LGBT main ships tend to make it obvious very soon to avoid queerbaiting accusations and mostly to get the viewers that comes with having representation. LGBT+ ship rarely get to have the slow burn M/F ship can have without people denying their existence and denying they can be canon.
SPN was supposed to end in season 5 that’s when Dean got a romantic “Endgame”. That means SPN won’t give them any lasting romance before the end. Not necessarily the last episode but the last season. That means that if Destiel is endgame they are writing it the way they would have had it been a M/F couple. And isn’t it how good representation is done? Indivualizing couples because every relationship is different, but at the same time not making a difference in the general way you write between a queer couple and m/f couple?
The only difference is that because of the burden of proof put on LGBT+ relationship people refuse to see Destiel as a possibility.