I in the USA we have the Safe Harbor laws for social and other user-generated content, the law protects the site/platform from user-provided content that violates a law in the USA. We have Terms(TOS), GDPR, Privacy, Data, and refund policies on all of our sites and we link Google, YouTube, Facebook, and others if we are using 3rd party tracking software. if you can comply with GDPR then you should be good if you are hosting they would follow your policies and if they are standing alone sites with the need to have all of it independently. I hope this helps...