Thanks for your suggestion. We tried using windowed mode and found that the frame lock was removed. We have updated the article accordingly.
Now that I got my hands on this game myself, I tested it and believe the windowed mode might actually just push the FPS little higher so it doesn't lock but if you can still get it to drop enough it will lock to 30. This causes FPS bouncing between 30-60 on lower end cards and feels awful.
But unlike in SoT beta, here I was able to remove this adaptive vsync even in fullscreen by disabling vsync for the game from nvidia settings or using their fast sync option. Users who actually experience tearing and need the normal vsync will have even worse performance if their fps drops. Hopefully they patch this issue.