Cloud vault backups retention

Hi @gwj and welcome to the Community! You may want to take a look at this thread:

I also don’t believe there is a way for Bitwarden to delete your specific vault from a backup.

IMHO, the most important thing is to have a very strong Master Password followed by strong 2FA. Also, it is a good idea to keep your own personal backup of your vault on a Flash Drive and store it in a secure location in case somebody does breach your vault.