I do believe that all this information is recorded somewhere. I very much doubt those records are in an accessible and queryable form that would allow the gover

I do believe that all this information is recorded somewhere. I very much doubt those records are in an accessible and queryable form that would allow the government to tell how long someone was a legal resident in the uk, and even more doubtful is them actually trying. More likely everyone will have to prove their right to residence, and the border database will not be available to us.