Well usually, when a developer releases a demo it is to promote the upcoming game that will come out in the next month maybe two. They would never release a demo if the game was coming out next year 6 months from now. Again usually. Not saying it couldn't happen, but it usually doesn't (a demo release a year before the game release I mean).
Now if this is a Demo of Ghostbusters the video game, then that means the game will come out this year at least. Why? because like said above it is unusual for a developer to release a demo if the game is coming out next year.
So far, nothing has really changed about the release date. Sure there have been rumors and speculation, and Sony possibility rethinking a strategy, but it doesn't mean this is all true. Granted, this has been the first news we have heard in a while. Keep the faith that maybe miracles can happen.