I think your reading is most true of those who identify with Harry specifically. The majority just identify with the HP world at large and are very basic normies, not particularly antifascist
Funny thing is, after reading HPMOR i'm having trouble getting a feel of what the canon world was like. And more specifically who i tended to identify with.
well, the whole subtext of the series (including FB) is encroaching magical fascism, and the embedded schema for how to deal with it is, ignore it for as long as possible, then militarise and explode into violence.