Microsoft’s Xbox Platform Partner Group program manager, Kevin Gammill, has announced that owners of the Xbox One X and the Xbox One S, who are on the "early preview ring", will get an update soon which includes 1440p support. The Xbox One X's supersampling feature delivers impressive results on a 1080p display, but it only supports downsampling to 1080p, so while those with 1080p displays benefit, those with 1440p get a lower than native resolution, and therefore don't get the most from their hardware.
Both of the consoles will receive support for 1440p displays, however, only the Xbox One X will support gaming in 1440p, while the Xbox One S will likely be limited to video playback. Once it has landed in the preview ring, the feature will spend some time being tested before finally rolling out to the general public.
Earlier this week, Brad Rossetti, Xbox Insider Program head at Microsoft, tweeted out to followers suggesting that something would be happening regarding Xbox One Insiders; it could mean that the update could drop soon.
If you happen to own a 1440p display and want to get this update sooner, rather than later, you can head on over to the Xbox Insider Program FAQ page to learn how to become an Xbox Insider.