Looking like CD Projekt Red has official confirm that their "Next AAA" game is actually CyberPunk 2077 Multiplayer. Looks like it was confirmed a little while back from their investors phone call:
RockPaperShotgun has some more information.
CDPR's mystery AAA title they have been talking about to shareholders since 2016 is Cyberpunk 2077's multiplayer. It's likely a standalone experience and singleplayer Cyberpunk will be fully released, expansions and all, before the multiplayer will be out. The multiplayer will likely not be out before 2022.
RockPaperShotgun has some more information.