Given how clumsy this "censorship" is, I highly doubt that this is a conscious effort of censorship, and is instead an automatic filter that was already in plac

Given how clumsy this "censorship" is, I highly doubt that this is a conscious effort of censorship, and is instead an automatic filter that was already in place to prevent malicious activity. Mastadon's original account was suspended for breaking the new TOS for linking to content that was in violation (the jet tracker), which then prompted many other people to break the TOS. I suspect there is some algorithm that twitter has had for many years that checks: IF link is highly associated with TOS violation, THEN flag content as "potentially harmful".