I'm very confident that the data is fully removed, because properly deleting data within NN days is treated as very serious internally. But I don't know the details of how it's done for cold storage.
(I would love to see someone subpoena something deleted, say, 1y ago and write up whether it was produced.)
(I would love to see someone subpoena something deleted, say, 1y ago and write up whether it was produced.)