It's really interesting to see pov from engine director. The fact that CDPR soon showed release date and they had less than 1 year to finish everything… Even ex cdpr dev said, when trailer with release date was announced, it was impossible to do that in 1 year. That and many things convince me, that the original release date was different, maybe 2022 because that date appears many times in leaked videos of development builds.
I personally guess, CDPR really wanted to release this game in 2020, because of investors pressure and ending cycle of ps4.