I can't speak for all states; just my own. When a person is killed by the negligence of another, by statute, the dead person's estate may bring a claim for wrongful death. The estate may recover various types of damages, as permitted by the statute depending upon what type of heirs remain, for the benefit of those heirs. But the estate, which would be the party plaintiff in such a suit (not the heirs; the heirs are just the beneficiaries), is absolutely bound by a validly written waiver of liability. So, yes, the waiver would preclude the bringing a wrongful death claim.
As do most states, my state also recognizes loss of consortium. However, that claim is described as "derivative," meaning that if the injured spouse's claim fails, so too does the consortium claim. Thus, if there is a waiver of the injured spouse's claim, that would cut off the consortium claim, too.
Where the waiver would not apply to a spouse's claim is where the non-signing spouse sustained personal injury herself. Unless she signed a waiver too, she could bring her own claim.