It's generally recognized that deleting data from a backup would violate the integrity of the backup, so allowances are made. Usually you have to make sure the data is deleted as part of the restore process. For example, from CCPA:
> If a business stores any personal information on archived or backup systems, it may delay compliance with the consumer's request to delete, with respect to data stored on the archived or backup system, until the archived or backup system relating to that data is restored to an active system or next accessed or used for a sale, disclosure, or commercial purpose.
> If a business stores any personal information on archived or backup systems, it may delay compliance with the consumer's request to delete, with respect to data stored on the archived or backup system, until the archived or backup system relating to that data is restored to an active system or next accessed or used for a sale, disclosure, or commercial purpose.