Cryonicist Thomas Donaldson (Ph.D. in mathematics from the University of Chicago) pointed out the bad assumptions with this sort of reasoning back in 1989:

http://www.alcor.org/Library/html/probability.html

Here is an example of the problem I'm raising, with the issues raised to an absurd level just for clarity. A new gambling house sets up in Reno. The owner undertakes to bet with everyone about whether or not he, the owner, will do his laundry tomorrow. Bets are made today and close at 6 PM. (Perhaps gambling houses already operate this way?) Do we, then, expect a rush of clients?

The problem with this bet is that he, the owner, has some control over whether or not he does his laundry. Not only are the dice loaded, but he gets to pick, after all bets are laid, which loaded die to use. Computing probabilities only makes sense when the events bet upon are known to be random. . . . this means that our actions can have NO effect upon the outcome. I don't mean "only a very little." NO means none at all, zilch, zero. Why zero? Because our actions now are seeds, not just "observational errors" which lead nowhere. Once we admit that our actions can influence these events, how do we predict by how much and when?

Within a very wide range, what happens to us is our responsibility. We are not passive betters on the outcome of events. I mean this both in the narrow sense of I, me, myself, and in the broader one of cryonicists generally. How can I (myself) affect my frozen fate 100 years from now? Well, for one thing I can choose my cryonics society. I can try to make its officers not only honest and competent as individuals, but operating within a constitution which keeps them honest and competent or throws them out of office. And I can provide enough resources so that evasive action is possible when any threat appears. Third, I can try to arrange that equipment, supplies, and competent people will be available when I'm declared legally dead. And of course last of all I can try to create other cryonicists.

But of course someday I will be frozen. What control do I have then? Not directly, but through other cryonicists who succeed me. We have all joined together for a journey across time. If anyone is revived 50 years from now, even with technology far in advance of ours and in another country, it will strengthen my chances. I believe the important part to remember about [conjectural] social catastrophes is that every one of us is putting out effort to see that they do not occur to us.

In other words, cryonicists can get off their butts and start to do some constructive things to make the project more likely to succeed. I've donated some money towards cryonics-related research that few other people seem interested in, for example. I'd like to see a lot more of that instead of the tendency for cryonicists, who jumped onto Drexler's "nanotechnology" distraction early on, to fantasize about "how cool it would be if we had nanotech factories which would give us genie-like superpowers." Nano-nonsense: 25 years of charlatanry