When Saber Interactive remastered Ghostbusters The Video Game, releasing it 10 years after Terminal Reality's 2009 original, the co-op multiplayer wasn't included.
As Matt McKnight, VP of business development at Saber, told Venturebeat at the time, the original multiplayer had been the work of a separate studio and was based on an incomplete version of the game. In addition, Saber found six different versions of the multiplayer code, and had no way of knowing which one shipped. The decision was made to leave multiplayer out of the remaster at launch, but whether it would be added at a later date was left up in the air, as Saber was "still in the process of evaluating the situation."
Now it's seemingly been confirmed as dead in the water. Speaking to MP1st, Saber's chief creative officer Tim Willits said, "This is something the team really wanted to include when working on that remaster a few years ago and had been attempting it, but the state of the original multiplayer code unfortunately just didn't cooperate. We did look into it but ultimately had to focus on recreating the single player experience fans were expecting from us."
Meanwhile, a new Ghostbusters game is being developed by IllFonic, the creators of Friday the 13th and Predator: Hunting Grounds. It'll presumably be based on the recently released movie, Ghostbusters: Afterlife and given their prior work, may well be a purely multiplayer affair.