Whether it was fascist or not matter because the word has lost its meaning. Could be something fairly innocuous really.

CNN sources a Media Matters report which goes into detail as to the content of the twitter account. Tl;dr, it's an explicitly neo-nazi account which regularly posted memes and content praising Hitler and the Nazi party and pushing neo-nazi talking points.

I'm not sure what it accomplishes playing semantic games about whether something fits the technical definition of fascism (Nazi Germany absolutely does, btw) when the commonly understood definition of far-right, ultra-nationalist, authoritarianism is abundantly clear.

lol yeah sounds totally righteous to dictate which opinions others should have

I don't think anyone is proposing that we dictate others' opinions. But companies, advertisers, and platforms are under no obligation to be associated with the expression of those opinions, and I have no issue stating that Nazis, Fascists, and their ideological descendants are very unwelcome on Beehaw.