If someone wants to setup a mammoth federation (because mammoths are less hairy than leftists or something - I dunno) they are free to do so. They can use the same software, they can set their own policies on if they want to federate with Anime/Trans/Communist/Nazi/Antifa servers however they want.
And AFAIK no Mastadon server have removed the ability to link to competitors.
But also, Truth Social violated Mastodon's license. Gab eventually shared their code, but their CTO took the chance to call me a slur on his public feed for asking.
https://www.thebulwark.com/truth-social-violated-mastodons-t...
But it is important to point out this is exactly how federation is supposed to work and people who support freedom of speech should support that.
It doesn't even make sense in this context, unless you are implying people shouldn't be free to read what they want (since federation is mostly about the reading).
And even if it wasn't, then yes I do believe that freedom of choice is more important than freedom of speech.