That’s not true it’s compatible with anything running ActivityPub. It currently has build a Mastodon client as a demo that’s why right now you can use it with Mastodon. They built Mastopod in a week. Part of the pitch it showing devs how relatively simple it is to build apps on top of it. So if someone builds a Pixelfed, Lemmy etc app then you absolutely can use it
Tf this has to due with free speech? Minds.com continues to operate, the government hasn’t censored them.