The GSC veterans have sent word that they are forming a new studio, Vostock Games, and will be making a game called Survarium, which is apparently a Stalker-like MMOFPS. Stalker 2 itself is "frozen" and the team will be focusing on the new game. They have tweeted: "All those asking about funding etc. That is not the issue. We were unable to secure the IP rights to continue with the Stalker franchise." There will be a Q&A session with Oleg Yavorsky and Joe Willburn tomorrow on Twitter to explain the Survarium project in detail.
The new studio have also circulated a video about their plans, which you can see below.