I'm gonna try and help Bounce out here.
What I believe he's trying to say is, there was a point in time when /mu/ wasn't an awful board to be on, where legit music discussion and suggestions of obscure music were a daily thing. Yes, it still had the people calling one another vile slurs, but the general vibe of the board then was one which helped genuine music fans find new music from artists that would never have gotten exposure in today's system, like Tuareg guitar music, forgotten jazz artists, obscure electronic releases, and more. By virtue of it being largely free from talks about cucks, crude racism, and vile slurs, it is a "relatively liberal" place that never really talked about the politics of music.
This point in time was also when Fantano's popularity boomed and a majority of /mu/ got on board with him. However, after that point, the demographics began to change and the board became less about music and more about memes and bemoaning SJWs ruining music. See: the CHVRCHES incident and the increase in shitposting. I used to subscribe to Fantano during this time and I could see the change in content that arose from this new /mu/ fanbase. I unsubbed after the Trigglypuff video on thatistheplan because that's when I saw the side channel as Anthony pandering to his 4chan base. He was doing these meme reviews because his base was demanding he do them.
The point I'm trying to make is, Anthony probably doesn't believe that Jews are responsible for all the world's problems. He probably doesn't think that all black people should die. He doesn't believe that white people are intrinsically superior because of their skin. That means he isn't a Nazi. His videos on his regular site indicate he probably sees music through a more liberal lens.
However, he is complicit in playing along with what his fanbase wanted. When you toss aside the videos where he plays into the hip-hop memes of shitting on J. Cole and shitting on teens who worships XXX, he is still responsible in pushing the words of Sargon and Sam Hyde to his followers while doing nothing to call them out on their shit. He's responsible for helping normalize of some of the alt-right's ideas by feeding into their bullshit about SJWs & feminists ruining things. At best, he's a moron who doesn't understand how much power he holds and is deleting the channel to rectify that. At worst, he's an idiot that tried to capitalize on & monetize his 4chan popularity by feeding them the same shit on SJWs, feminists, and memes and is now trying to backtrack on his shitposts.
Either way, the man isn't a Nazi, he's just a complicit dolt.