We have full rights to The Witcher games. But please consider us as rational people, we sometimes have weird ideas but overall our thinking is very rational. We invested 15 years of our lives in it and a lot of money.
He also reiterated that the studio values The Witcher highly. Cyberpunk 2077 is in many ways The Witcher's opposite, so it fits the bill.
After three massive RPGs in the same universe and the same character, you naturally want to do something new.