Easy:

- Rotate old tapes to store the freshest backup (according to retention policy)

- Store row ID for each deletion request

- Replay deletions during restore

Either way you want (or already have) a scrubbing procedure to import production data into a staging environment, so this is not a technical issue.

Yeah during restore. But is this still compliant with GDPR deletion request when you still physically have access to a copy of user's data?

I mean, sure, it's very theoretical, you can't prove that Meta or Google doesn't delete your data until a leak.