The risk of planes falling out of the sky due to the all of the pilots on board being vaxed and simultaneously keeling over dead with no warning signs... is less than your chances of winning the lottery with a ticket you found in a parking lot. :>)

Never going to happen. It's a good thing to worry about though.

Now, the chances of several pilots actually having heart attacks, breathing problems, blood clot issues, neurological problems during a flight... and then the FAA having to GROUND every vaxed pilot pending a full physical... is actually about 50/50.