This is all speculation. We'll see soon enough how this all plays out - I was just expressing my doubt that any country will say "if you had COVID 3 years ago, you're free to travel". They might lift restrictions completely, but if they keep restrictions, I don't expect them to be lifted for people who had COVID really long ago. There will be other rules, but "had COVID more than 180 days ago" seems an unlikely one. That's all.
There have been studies which claim that prior infection by SARS1 (2003) has conferred some immune protection against SARS2 (2020). That would be 17 years, not 180 days.
With billions of dollars at stake on multiple sides of proposed policy, there is sufficient financial incentive to study very closely the mechanisms of both natural and artificial immunity.
Policy makers can selectively highlight or ignore science, but not forever. In the US, some early policies were overturned by later court rulings, as data became available for lawsuits.
