I'm pretty sure the Devs are Communists and are very anti-nazi, anti-racist, anti-facist.

They most definitely are. In fact, a good portion of the community in lemmygrad is LGBTQ+ (over 20% by a recent anonimous survey done on lemmygrad) and every single one of them is respected there and has a voice.

Additionally, I'm fairly confident that they have separated those beliefs between lemmy.ml and lemmygrad, and I'm fairly confident they do a good job of moderating Lemmy so it doesn't become lemmygrad2.

Not completely, to be pefectly honest, but generally (as in really close to 100%), yes. Though I have to admit that there were some cases where the admins on lemmy.ml did overstep their power, I will admit to that. But these were very few cases and I believe things could have been settled through conversation.

As for the Lemmy software, it is Free Open Source Software. It's built for everyone. Literally the most socialist/communist thing there can be - advocating for public ownership.

Exactly my thoughts. The software is GPL licensed, it doesn't get any more communist/socialist than that. By the community, for the community. Sure they get to call the shots on the repo, but you don't like it? Fork it 🤷.