Title says it. Apparently lemmy devs are not concerned with such worldly matters as privacy, or respecting international privacy laws.
But I think in terms of federated content, you cannot be expected to do more than send information about the deletion out. If other instances don’t respect it, it’s not the originating instance’s job to police it.
It actually is.
When delegating the processing of PII to someone else (like another instance), you’re supposed to initiate a data processing agreement with them: https://gdpr.eu/what-is-data-processing-agreement/
Unless Mastodon has somehow automated this process in inter-instance communication, they are just as liable as Lemmy is.
But pii isn’t being sent. A user’s nickname and the domain of their instance plus any content they create is. If they choose to put their pii in public posts or user info, that’s their choice but is not pii solicited in order to operate the service, it was volunteered.
It’s a crucial difference. I considered this when writing the terms and data retention information for my own instance. Federation is very frugal about the information shared.