Those claims disappeared rapidly when it became clear they offered some protection, and reduced severity, but not immunity.
People seem to be taking a lot more “lessons” from COVID than are realistic or beneficial. Nobody could get everything right. There couldn’t possibly be clear “right” answers, because nobody knew for sure how serious the disease could become as it propagated, evolved, and responded to mitigations. Converging on consistent shared viewpoints, coordinating responses, and working through various solutions to a new threat on that scale was just going to be a mess.
I'm in no way taking a side here on whether anyone should have chosen to get vaccinated or wear masks, only that the information at the time being pushed out from experts doesn't align with an after the fact condemnation of anyone who chose not to.
Do we know that 0.1% prevalence of "unvaccinated" AI agents won't already be terrible?
I may be out of touch, but I haven't heard about masks for measles, though it does spread through aerosol droplets so that would be a reasonable recommendation.
Personally I at least wish sick people would mask up on planes! Much more efficient than everyone else masking up or risking exposure.
The claims being shared by officials at the time was that anyone vaccinated was immune and couldn't catch it. Claims were similarly made that we needed roughly 60% vaccination rate to reach herd immunity. With that precedent being set it shouldn't matter whether one person chose not to mask up or get the jab, most everyone else could do so to fully protect themselves and those who can't would only be at risk if more than 40% of the population weren't onboard with the masking and vaccination protocols.