I think this is an interesting hypothetical. If you never sync up, though, are you still part of the app developers aura of responsibility? Deletion of the data has been initialized per requirement, and will propagate through the system at the rate the system is able to propagate data.

If someone changes their system to avoid the data being deleted, presumably that would then have to accept the liability / responsibility for deletion. But that’s already moot anyway, because we’re not talking about a court of law, but a court of App Store publication, which it would already no-longer be a part of.