Developer Insomniac Games has stated on Twitter that it would love to release their open world shooter on PC, but commented that the decision would ultimately lie in Microsoft's hands.
The studio said "We'd love it if it could happen but [the] ball is in Xbox's court on it" to a fan on Twitter , suggesting that the team does not have full control over where the game releases.
Microsoft reportedly allowed the studio to own full rights to the game, which is supposedly part of the reason they decided to make it an Xbox exclusive. If this is true then it is not entirely clear why Insomniac would not be able to decide to bring it to PC themselves, but as Microsoft is the publisher they may have overall say on the platforms it releases on.
Although Insomniac stated that they had no plans to release Sunset Overdrive on PC at the time of release, they did say they would be open to the idea down the line. Just days before the game came out in 2014 an advertisement was put up stating that the game would be coming to Xbox One & PC, but Microsoft then confirmed that this was a mistake.
So although a PC release remains a possibility Insomniac Games will be focusing on their upcoming Oculus Rift games for now, which are The Unspoken, and Feral rites along with the PS4 exclusive Spider-Man.