They can, but not by lying or being in contravention to their own policies.
Even regulators hold businesses to following their own policies.
You have a business agreement between the user and the company. The company can’t end the agreement by legally maintaining they ended it because you maintained a pedophile site, if there is no example of a pedophile site.
That is suable.
There is the crux of the problem.
Many social media companies lie or ban or shadow ban in contravention to their own policies.
We all know this. Workarounds must be sought.