They're not going to be recorded in the sense of being taped, but being recorded in the sense of a note being made of their occurence. In the same way that hopsitality with businessmen is disclosed on member's interests.

So no, not it doesn't open the door to official surveillance.

Nor would it do so if the person giving the briefing actually were being taped and then chose to make it public. The point about protecting sources is that it only applies if the source wants.

If the PM chooses to be open about who he meets and what is said at those meetings, then that's democracy.