The wide-spread vaccine campaign by Leftist-fascists will be remember in history in-line with our treatment of native americans, african slaves, white indentured servants (primarily Irish), and internment-camp Japanese. And the fallout will be measured with deaths in the coming years.
With that said, after perusing that wikipedia page and accounting for the growing participation numbers of this event, one can't discount the probability that less-qualified people are entering this grueling distance and struggling mightily.
I've noticed a general "distance inflation" in the casual-running population. We've gone from a "couch-to-5k" culture to a "couch-to-marathon" culture for the minuscule (and undeserved) reward of saying "I did it". As an example, I particularly remember a few years ago a colleague at work (recent grad) trying to talk to me about the marathon he was going to "run" after a week of partying with his friends on vacation and with limited training/preparation (near zero). It was a pure "I did it" play. I couldn't really have a conversation with him because what he was doing (less than bare minimum) and what I was doing (training for competitive road races and track meets) were completely different things (akin to me talking to Wade Boggs about my hitting-average in a carnival batting cage).
As ultra-marathons move on to more and more people's "running bucket list", you're going to get more and more "left-tail distribution" runners that are unwilling to do the necessary work and yet will be entering in increasingly difficult events - and some will inevitably die - as they would in any other kind of event involving this kind of shift.
Although, I'm open to it still being vax-related. I'll give it ex ante 50/50 split.