A particularly unpopular practice from the big platform holders is to pay third party developers to release exclusive content on their platform. A good example being how the PS4 often receives timed or straight up exclusive content for Bungie's Destiny. Much to the surprise of many, it appears that Fallout 4 will thankfully not be receiving any platform exclusive DLC. Pete Hines, VP of marketing at Bethesda replied to a question asking about platform exclusive DLC, to with he replied with "We aren't doing a DLC exclusive with anyone".
While it's a relief that all platforms will be receiving the same content, the possibility for timed exclusive content is still there. Bethesda's last big open world RPG Skyrim released most of it's DLC on the Xbox 360 before any of it made it onto the PC. Guess we'll see how it plays out.
Fallout 4 will be releasing on November 10th of this year for the Playstation 4, Xbox One, and PC.