It is a string of assumptions based in little fact.
It is the slippery slope assumption. You are correct, assumptions are being made in such predictions.
You believe that none of that will ever happen? Some vaccine passport requirements are already being imposed, such as those in New York City.
I would love to come back to this thread in a year or two, and be proven to have been completely wrong about fears of what is yet to come. I would love to come back and tell you that you were completely correct that all of these fears are overblown.