Since you host with discourse they do collect data as its needed to host on your behalf (like contents of posts, usernames etc). Never read the privcy policy in dept so I dont know if you or DIscourse owns the data. I can say you can always get a copy of the data. In the privicy policy they do say:
How can I contact CDCK about privacy?
You can send questions, requests, and complaints to:
Civilized Discourse Construction Kit, Inc privacy@discourse.org
European Users with questions or complaints about GDPR compliance should also address CDCK’s representative in the Union via email at regis.hanol@discourse.org or via mail to
M. Régis Hanol Civilized Discourse Construction Kit, Inc 78 Allée Primavera Centre UBIDOCA, 15232 Pringy 74370 ANNECY FRANCEFor complaints under GDPR, European Union users may lodge complaints with their local data protection supervisory authorities.
Thats correct.