I am nonbinary, I haven't played a Dragon Age game before Veilguard, I haven't yet gotten to this one scene that's apparently damned the entire franchise, nor have I even met Taash(?) yet. Here's my off the cuff rambling thoughts:
I've just now watched the scene devoid of context, and if that's where the misgendering conversation started and stopped, I think everyone is wildly overreacting. The first minute is fine, a weird older lady apologizes for screwing up in her own way, I've had people react in much stranger ways than that, and in it's own way "Whoops I fucked up, lemme do some push ups to show I feel bad" is kinda sweet. I'll concede that the explanation after was heavy handed, but you could definitely include the gist of it somewhere else easily. "Don't be weird, just say sorry and move on" is the correct advice to give to someone who doesn't know how to interact with trans people but wants to be supportive. If that last minute of the conversation happened somewhere else in the game, it'd have been fine.
The game overall has been mediocre so far, a solid 6 out of 10, nothing to write home about, but certainly not deserving of the flak it's been getting. This is one of the first games I've played where I feel like I'm represented, I think it might be the first major game where you can make a custom character who's explicitly transgender, and that counts for something in my book.
From where I'm standing, it really feels like a lot of the outrage DA:V is drawing comes from some discomfort(conscious or no) with having the queer experience very out in the open for everyone to see, which is what I would expect from a series that (as far as I can tell) has always had tons of explicitly queer characters. I'm sure that's not universally the case, but I simply don't buy this narrative of "I'm fine with trans people, but the way it's written is so clunky." because I've had almost the polar opposite experience. I can think of few other games that talk about transness in the way that actual trans people talk about it.
Ah, my only context was what little I've picked up about Krem and Dorian(as well as an explanation about how the Qun is sexist to the point of wrapping around to be progressive), and assurances from people that the games have always been like that.
Even still, from a 15 year old series, that still manages to be a lot gayer than most.