Fascinating look inside the world of Cryonics (the freezing of the body to “cure” death later) by Josh Dean:
I don’t think it’s overly reductive to state that there are three possible outcomes for those who choose the freezer over a coffin:
One, science never overcomes the obstacles that stand in the way of bringing patients back and they are either thawed and disposed of the way they would have been disposed of originally. This is not a terrible outcome. They’ll have no idea it even happened.
Two, the patients are thawed in whatever state they may be (fully preserved, kind of preserved, badly preserved) and fatal issues are cured using newfound treatments, while nanotechnology repairs all the cellular damage, catastrophic and otherwise. If the body is old and decrepit, they’ll get a new one, composed of parts grown in a lab, or maybe just synthetic. This is Avatar.
Three, the body doesn’t matter. All that does is the brain, and some sort of heretofore unimagined technology will allow future humans to thaw and then access the data inside the brain and upload that data directly into a machine, or the machine, or whatever.