After reading your post and then reading more stuff, it appears that Mastodon is going to become the Gab.ai for Leftists.
Which seems to be ironic in a way.
The internet cannot be controlled if it is to remain free and open. Creating censor lists like this here https://github.com/tootcafe/blocked-instances ,is no different to traffic shaping that ISPs do and what the FCC in America has done.
Effectively they have created BBS boards with a bit more tech and have isolated them.
If this sort of mentality continues we are going to have a segmented internet as a whole, where mega corps rule.
Imagine a hellhole like this:
-- Connecting to Monsanto ISP -- Connected > -- Type "www.reddit.com" -- Coca-Cola DNS, im sorry I cannot resolve that domain for you, please buy another Coca-cola. -- Buys Coca-cola -- Connection to www.reddit.com blocked, it is now under the federated space of GlaxoSmithKlein, who are in competition with the Monsanto Liandri Corporation. -- Goes to connect to www.guardian.com -- Hit with adds for Monsanto weedkiller, and GMO sweetcorn.