The source of plausible moral obligation becomes much more obvious when you stop referring to the patients as "corpses". Corpses are associated with irreversible death -- we don't traditionally have a duty to revive corpses, but that is only because doing so would be impossible by definition.

If there are billions in need of revival, more resources will go towards finding a way to do it in the first place. Also, revival mechanisms that can only pay for themselves with greater economies of scale can also be employed.

If I have to learn a new set of skills, language, customs, etc. to live again that is a sacrifice I'm more than willing to make. If the people of the future are non-sociopathic humans, they will be willing to revive and reeducate me. However, I see no harm in setting up a trust that creates financial incentives as well, and covers any expenses. A few hundred years of compound interest can add up to a lot. The more people are involved in this, the more economies of scale (i.e. group schooling, revivee communities, specialists trained to deal with us, etc.) are possible and profitable.