The screenshot you posted says that the provision against hosting copyrighted content without permission includes pornography, not that pornography itself is against the terms.
And it sounds like the move is a precaution being taken because of a disgruntled ex-admin, not by force.
It depends. The provision is against infringing on the rights of others or otherwise violating the law, which those things may or may not do. Porn and online gambling are both legal (albeit regulated) in Germany, where Hetzner is based. Hetzner sucks anyways though so they don’t have my sympathies.