If you're buying a RAID card from an OEM (Dell, HP, etc) I've often seen them reject non-branded drives, or explicity state that your warranty is not valid whilst that drive is connected to the array.
That said, for generic cards (Adaptec, LSI, etc) I've never seen a drive be rejected just because it wasn't on the HCL.
I have seen drives rejected because:
- The were the wrong compatibility (LVD or HVD, SATA or SAS)
- They were larger than the largest drive size supported (a common situation if the controller is older and only has 48-bit addresses)
But not because they're not explicity on the HCL (after all, it would be impossible to keep the HCL up to date enough to accomodate every new model of HDD).
Depending on how picky the manufacturer is they may reject any warranty claims if the non-HCL drive is still attached to the array.