In a PlayStation Blog interview, Code Vein II producer Keita Iizuka and director Hiroshi Yoshimura confirmed the game has multiple endings. You'll unlock a New Game+ mode after your first playthrough, and it ties into the choices you make that can change the story's history.
Iizuka focused mostly on the multiple endings. He said your ally Lou will help you go back to the past at certain points. It sounds like you won't always need to start a whole new game to check out different outcomes. He explained, “When you intervene in the past and return to the present, relationships with characters or the world itself will change. The game has multiple endings, so even after reaching one ending, you can go back in time to alter it.”
As for the Code Vein New Game+ option, we only know a few details. It exists. Character levels carry over. Keita Iizuka also said “certain progress” will stick around, but it's unclear if that means abilities or equipment.
Part of the interview repeated that Code Vein II works as a standalone experience in a “new setting.” Director Hiroshi Yoshimura pointed out some familiar elements from the first game. He noted, “That said, it’s not an entirely separate world either; fans will notice familiar items, weapons, gifts, and other small callbacks scattered throughout the game.”