The short answer is “Alcor will revive them.”
The third item in Alcor’s mission statement is: “Eventually restore to health and reintegrate into society all patients in Alcor’s care.”
The Alcor Care Trust, which is responsible for funding revival, grows in real value over time — compound interest should eventually produce sufficient assets to cover the costs of revival. At the same time, as technology progresses the cost of reviving patients should decrease over time. Eventually, the increasing funds available in the ACT should be sufficient to pay the costs of reviving and reintegrating patients into society. Even at 3% return, assets will increase by around 1600% over a century.
Socially, Alcor is a community. Some members of this community are alive and healthy, while others have been cryopreserved. This community forms an interconnected network of friendships and close ties. At any point in time the healthy members of this network have friends, relatives and loved ones in cryopreservation and will seek to revive them. Once revived, those members will in turn have other friends in cryopreservation, and they will in turn seek to revive them.
The plan is not for “them” to revive us. The plan is that we, the Alcor community, will revive ourselves.