There was initially a thread on this site when it was a forum, before the 2020 Impreza was released. As I was very impressed with the lane centering ability on the 2020 Legacy, I was hoping the feature would also be present on the 2020 Impreza. Initially I had gotten word from customer support that it would include lane centering, but based on the information I have seen thus far, it does not appear the 2020 Impreza has lane centering.
The 2020 Subaru vehicles that do have lane centering are the Legacy, the Outback, and the Forester.