A few months ago, CD Projekt Red announced that a new Witcher game is indeed on the way. They then wrote that "a new saga begins", which suggested that the plan might be to release not just one game, but several. And now they have confirmed that this is actually the case.
In connection with their half-yearly report, they arranged a presentation for their investors and then also answered questions from them. When asked "what do they mean by a new 'Witcher saga'", CEO Adam Kiciński replied that they are now working on the first game, but that they have several games in mind.
He subsequently refers to the existing trilogy as the first saga and the upcoming games as the second. He also confirmed that the game is still in the pre-production phase, which means it will be a while before we see it.
So far, we haven't gotten much information about what the first game in the next series will be about, but based on the image they used to announce it, it seems to revolve around the "School of the Lynx", or the Witcher school of the lynx. We also know that the game is being developed in Unreal Engine 5, and if you want to know why, you can read about it here.