Lemmy should implement proper post deletion, possibly with a delay to allow moderators and admins to inspect deleted posts, but expect anything you share via ActivityPub to follow the once on the internet, always on the internet rule even more than in the past.
How would this be done? Like you mentioned, anyone can run a modified instance of Lemmy that does not honor delete requests. I suppose you could put something that retrieves content from other servers as a pull operation instead of a push, but that’s going to break Lemmy’s ability to work with other ActivityPub applications (at the very least).
There are no guarantees either way. Even if the delete was somehow enforceable in software, it can be defeated with a simple server backup of any federated server.
I think federated servers should respect any delete request, but as users we need to expect that they wont.
Zak@lemmy.world 6 months ago
Delete currently renders posts invisible to most users. Delete should actually delete the post from the server.
It’s impossible to ensure that the post is deleted from federated servers, web caches, clients that cache things, etc…