It's been more than a decade since one of the main Halo games was released on the PC and until very recently there seemed no chance of that changing. However, an update to the existing Amazon listing for Halo 5: Guardians suggests that that may no longer be the case.
The change took place over the weekend and saw some subtle box-art tweaks to the listing. Where previously the Xbox One version of the game was listed as being available "only on Xbox One," the latest product shot now claims that it's an "Xbox One console exclusive," instead. That would suggest that as before, the game is available on no console but the Xbox One, but it also leaves room for it to be available on other non-console platforms too. Like Windows PCs.
As Ars Technica points out, this may be Microsoft just extending its Xbox Play Anywhere system back a couple of years, as Halo 5 just missed the cut by virtue of coming out a little earlier than the program and therefore was unable to take advantage of the scheme's Xbox and PC twinning system. Other, more recent games, like Sea of Thieves, have been able to enjoy that platform uniformity.
And now Halo 5: Guardians may too. Until now, anyone wanting to play an approximation to the game on PC would have to use the Forge mode that was far from ideal when it came to multiplayer and required a lot of jumping through hoops.
With an official launch of Halo 5 Guardians on the PC though, players would be able to enjoy the campaign with a mouse and keyboard like never before.
There's been no official announcement as of yet, so there's no hint of a release date for now.