Quote: "They may hope /wish one day that they could somehow become unvaxxed. Is this a possibility?"
The Laws of Physics state that every process is reversible.
It is just that some things are not worth doing. I read an Physics article a couple of years ago, which explained how they could unscramble an egg. The trouble was that you could buy a few million eggsess, for what it cost to unscramble one.
Therefore one may be able to become "unvaccinated". But, it would probably require dismantling you to Quantum level.