[Silhouette]

I'm sure the GDPR disagrees with me here, but I'd like to see a watchdog test that case in court.

I doubt it. The right to erasure has never been absolute even under GDPR. Typical examples are that you can't compel a bank to delete all records of a loan it gave you, nor compel the police to delete a criminal record of your past behaviour, as long as the data is lawfully and properly handled.