Digging through the CrackBerry Forums there's a lot of questions surrounding whether or not unlocked BlackBerry 10 devices will be able to get the BlackBerry 10.3.1 update directly from BlackBerry. Thankfully, that question was asked directly to BlackBerry Product Manager, Michael Clewley, who noted ShopBlackBerry devices would get the update direct. We followed up with Michael on that to ask about Amazon devices as well and to ensure that the information was indeed correct before posting and now, both ShopBlackBerry and Amazon purchased devices globally will get the update directly.
To be clear, this doesn't include carrier unlocked devices. And by that we mean if you bought it from a carrier and unlocked it yourself, those are not included here. Only devices that come factory unlocked from ShopBlackBerry and Amazon are being described here. If you're not seeing the update yet on those devices, keep checking as it was only recently enabled.