Since upgrading to Windows 10 (from Windows 8.1), it seems my Minecraft installation (v1.8.8) is now in a letterbox format while in full-screen mode. I have no made any changes to the resolution and all of my configurations are the same as they were pre-Windows 10.
I'm aware that I could change the resolution manually through the launcher for windowed mode but I'd much rather not forfeit full-screen because of an oversight by Microsoft.
I've spent this past week doing additional searching and simply cannot find any sort of answer for this, even having sat in the Minecraft "tech support" IRC channel for countless hours without a response. At this point, I'm going to assume that there is no resolution for this given I've been unable to find any mention of it elsewhere.