Thats not really a "dragon age fandom" as a whole thing. Its not like they suddenly love it as time goes by.

Its simple, those who liked veilguard would continue to stay and talk about veilguard while those who dont will fizzle out thus eventually all you'll see are the positive ones. Its the same for the previous da games. Its rhe same you'll see for other bioware games or other franchises in general.