Amazon is known for posting release dates for future products, even if they do not have any official information about their release date. Its latest product listing appears to add a release date for the Halo 5: Guardians title.
The Spanish branch of the online retailer has apparently listed that the release date for the latest Halo title will be Thursday, September 10th 2015. However, that listing has recently changed to “la venta el 31 de diciembre de 2015”, which means that they now point to a December 31st release.
While the release date is just pure speculation, it might somehow indicate that Microsoft and 343 might be looking to delay the title a bit. Take the information with a grain of salt though, since the release date might as well be something completely different and Amazon ES can at any moment take down the product listing as well.
Thank you Gamingbolt for providing us with this information