TR1 Form - occupant info - Where does this go?

We have had a couple renting a winter let from us under the rent a room scheme and we are in the process of selling our house. They are happy to move out upon completion and have signed the HM Land Registry TR1 Form as such today.

Please can you advise where their details will be stored following this signature? Just out of curiosity, is it used outside the Land Registry, does anyone know? Does (departing) occupant info get recorded somewhere for posterity? I assumed it was more of interest to the conveyencer that the couple are leaving, than of interest to any other party who they are.

They are not registered as living here on the electoral roll (for their own legitimate reasons) and their employer, GP and bank is registered at their parental addresses for ease. So this would be the only time their names have ever appeared on a formal document besides the TA6 Property Information Form for the conveyencer earlier this year. So, I wonder if this information will now be centralised? I would like to let them know, if so.

Also, does the TR1 get uploaded now, or not until completion?