The Playstation Store are already allowing players to purchase the Season Pass for Guardians of the Galaxy: The Telltales Series. The more interesting thing is that it has noted that the game will release on April 18.
The Telltales Series game will run in conjunction with Guardians of the Galaxy Volume 2 which will also release in April.
Please keep in mind that neither Sony nor Telltale have come out and officially announced a reason date. This rumored release date is highly likely as it comes from the Playstation Store.