It looks like Microsoft is about to make a welcome change to the Xbox One controller, with the updated version — which includes all controllers made after June 2015 — coming with a dedicated 3.5mm audio jack. The port is already listed on the Xbox support site:
3.5-mm port (16). Used to connect compatible 3.5-mm audio devices. Only available on controllers released after June 2015.
While Sony's DualShock controller for the PlayStation 4 allows users to connect their audio gear through a 3.5mm jack, Xbox One owners had to resort to buying the Stereo Headset Adapter to hook up their headsets, which incurs an additional expense of $24.99. By including a dedicated 3.5mm audio jack, Microsoft is fixing a major pain point with the controller.
With E3 just around the corner, it is likely Microsoft will make the announcement at the video game conference next month.