
Id Software left the project, Carmack left the studio, and DOOM was then redone from scratch, following a completely different philosophy, closer to that of the original chapters.
In the video, released in August 2020, but with material from 2011, we can see some technical evidence of what the game was supposed to be like, particularly some creatures and how they interact with the environment. There are also sketches that show the scenario and a human character in particular, but we don't know anything about them.
Probably if this DOOM had become a reality, today we would not have the DOOM of 2016 and DOOM Eternal, with the series which would have taken a completely different path.