Braking on descents was already programmed because there was a video of a guy comparing the times with and without autobraking down alpe and you could see how line got red that indicated when you had or you were braked. I also remember that it was pretty good made because braking kicked before the corner and then brakes released before entering the corner like irl but it never got released
You can see here that they were working on it but never released Competition & AI Tech Update: November 2022 Recap - #5
BTW i really liked the Competition & AI Tech Update that they did every month telling us the users what they were working on and how development of the features was going.