It's not that easy with GDPR, the dat protocol to my knowledge knows how to update but not how to delete. A delete is essentially a soft-delete in that case.
Yeah I guess there are questions how delete works in a distributed system like this.
E.g. if I have the archive on my computer/server I control and delete it then bingo - the data is gone and the app cant access my data any more. However, what happens to nodes that are seeding my data? Presumably they'll hang onto it for as long as they want, and there would not be a way to "force delete" the shared data since that would break a lot of the other benefits. Same goes for any hypothetical "prevent seeding" type options.