At first a rumor is circulating that says Hideo Kojima was fired by Konami. The reason apparently was that he was working alone on the PT game directly with Sony in order to launch it on PSN; he was reportedly working on this project without anyone from Konami or his team knowing about it.
As nothing has been confirmed yet, we cannot be sure of what is happening; however, the site guarantees that it talked to people who are related to the development of the PT game. Given the information, the game was being developed by a small team and its release date was confidential.
Apparently Konami learned about the game in 2014 at Gamescom, until then Kojima was still Konami's vice president. As well as rumors about the game began to emerge and the public began to collect information about the game in which Kojima was secretly working with Sony; something that caused embarrassment on the part of his team at Konami who knew nothing.
When all of this happened, Konami was focused on developing a mobile game that would be low cost but would make a big profit; having no intention of investing in a new triple A game, even if the idea came from Kojima it would not be well received.
What enraged Konami the most was the fact that Hideo Kojima would be using the money from Metal Gear Solid V to develop PT; this was something that generated a lot of tension between Konami and Kojima, but today it is better.
See also: BGS officially canceled in 2020