The whole concept does seem to depend heavily on aspects of trust, and thus on peoples' reputations for trustworthiness.

For example, I imagine myself waking up in a cryonic revivication facility a few decades after I otherwise would have died, and learning of a group of a half-dozen people still vitrified who made promises while I was cold to help me out if they were woken before me. One important question seems to be, how much would that promise nudge me towards feeling like assisting those people ahead of any others?