If you’ve got a RAID array with 1 or 2 parity then manufacturer recertified drives are fine; those are typically drives that just aged out before being deployed, or were traded in when a large array upgraded.
If you’re really paranoid you should be mixing mfg dates anyway, so keep some factory new and then add the recerts so the drive pools have a healthy split.
If you’ve got a RAID array with 1 or 2 parity then manufacturer recertified drives are fine; those are typically drives that just aged out before being deployed, or were traded in when a large array upgraded.
If you’re really paranoid you should be mixing mfg dates anyway, so keep some factory new and then add the recerts so the drive pools have a healthy split.