Yes, claimed censorship.
There was no actual censorship. As I have said before, the Barrington declaration is trivial to find. It is still available in full at https://gbdeclaration.org/ to anyone who wants to read it.[1] If Facebook etc don’t want to host it, they don’t have to. Anti-vaxxers and lab leak theorists are still able to present their ideas on innumerable other websites and other publications.[2]
Refusing to publish, advertise or provide a platform to someone is not censorship.
Persuading or pressuring third parties not to publish, advertise or provide a platform is not censorship.
Preventing the authors and their supporters from publishing, advertising or speaking out on their own presses/platforms would be censorship - but did not happen.
The censorship prevented the scientific dialogue. Scientific dialogue was prevented from happening by the censorship.
There wasn’t any censorship. But even if the restrictions on posting on twitter/facebook/etc had been censorship, they wouldn’t have prevented the scientific dialogue, which took place elsewhere.