My sense from a lot of epidemiologists is that this does not seem inevitable, particularly sans bioterrorism or biowarfare, before technology renders it impossible. The claim is that there will be a plague killing a higher percentage than the Black Death in Europe, despite modern nutrition, sanitation, etc, and an order of magnitude worse than the 1918-1919 flu. H5N1 flu has had case-mortality rates in diagnosed cases that match those numbers, but more people were found with antibodies than were diagnosed, suggesting that the real case-fatality rate is quite a bit lower, and not everyone gets infected in a pandemic.
ETA: Also, fatalities in the 1918-1919 flu were worse in the poor parts of the world, and cryonics facilities are located in prosperous countries. There are also generic reasons to think that there are virulence-infectiousness tradeoffs that would shape the evolution of the virus. However, the recently reported lab-modified H5N1 experiments count as evidence against that (they were justified, despite the danger of revealing a bioterrorism method, as a source of evidence that an H5N1 pandemic would be highly virulent).
ETA2: And the flu experiments actually demonstrating that breeding the virus for airborne transmission reduced its lethality.
He has resumed posting at his blog Chronopause and he is essential reading for those interested in cryonics and, more generally, rational decision-making in an uncertain world.
In response to a comment by a LW user named Alexander, he writes:
(Sidenote: This reminds me of what Luke considers his most difficult day-to-day tasks.)
On a related note, Carl Shulman has said that more widespread cryonics would encourage more long-term thinking, specifically about existential risk. Is it a consensus view that this would be the case?
Every now and then people ask LW what sort of career they should pursue if they want to have a large impact improving the world. If we agree that cryonics would encourage long-term thinking, and that this would be beneficial, then it seems to me that we should push some of these people towards the research and practice of brain preservation. For example, perhaps http://80000hours.org/search?q=cryonics should have some results.