With the exception of a couple very high-end brands, the OEM will never concede their product was at fault. The number and types (e.g., whole house electrical inspection) of proof they will demand will negate the value of the item damaged.
Note: in major surges, the protector should "fail" thus protecting the equipment. Which is different than failing to protect.
But, to directly address your question, yes, the strip could be out of warranty, but the equipment could be (in theory) covered.