That's not the answer to the problem.
He might be lying or he might not but if the game is truly dead is only up to the developer. The REAL question here is if you should support/follow him or his work or not. So it comes down to if you have the faith that the game is still being worked on or not.
-You think or hope the game is still in development? Then stick around and continue following the thread.
-You doubt the game is still in development but feel let on? Leave the thread and check back in a year.
-You are sure the game is abandoned? Leave the thread.
It's that simple. Don't follow a thread just to see if you were right or not as that helps no one and only show people cannot let go. Dare to let go. Move on to better games and threads.