I agree that it isn't absolute proof. It is possible that an effect like the one you described took place. But it isn't the only evidence. I'd direct you again

I agree that it isn't absolute proof. It is possible that an effect like the one you described took place. But it isn't the only evidence. I'd direct you again to people like Alex Jones. I think it's extremely hard to argue that Alex Jones and his toxic brand of disinformation didn't benefit enormously from access to platforms like Facebook, Twitter, and Youtube. I think you'd be extremely hard pressed to argue that his reach has increased as a result of being de-platformed. You may be able to make the case that it has retrenched the support of his hardcore followers, but that is not the same thing as signal boosting his message in society at large.