I think you are turning around cause and effect. Fringe political extremist where turned into "heroic defenders of Ukraine the day little green men showed up to separate Crimea and the Donbas from Ukraine. If anything the Russian invasion have them legitimacy. It clearly says so in the links you provided.
Edit: And Putin stated Ukraine was not a country as early as the 90's even though the USSR fell apart and countries that where autonomous before, became independent again.
Turned in the perception of Ukranians. The Azov movement was seen by many Ukranians for what they where.. right wing extremists they had no legitimacy. But when Russia invaded they fought the Russians tooth and nail, legitimizing them.
Biden articulated what Putin was saying himself. Joining NATO is the choice of a souverein nation and using that as an excuse for invasion is just that.. an excuse.
So no, I don't think I see it reversed. And what we are seeing unfold is clear. You claim to be anti imperialist but when Russia does it it's OK?
The war is horrible and can end with Russia withdrawing to within their own borders, but that won't happen as Putin will be punished by his "own" and replaced with someone else to do it.