As for FreeFlarum, we don't enforce anything related to the above-mentioned. It is up to forum owners to make their forums "compatible with laws", if they use extensions that contain additional features or if they expanded their forums by another ways and might require some kind of a warning for the users. We reserve the right to cancel forums that do not comply with that, if a complaint is made.
I agree with what others said - usually, it is enough to use FoF Terms, if you need it. I read that there is also a GDPR extension in the works, and we might include that at FreeFlarum later