For the past 2 (?) years, before OnePlus release a phone, there is a headphone jack survey. This year there is no difference.
With an 88% acceptance rating, one would think the headphone is going to be around forever. It seems nothing is forever. The next model 6T will come without the jack. There will be a USB C dongle in the box for the 3.5mm headphone jack. link Alternatively, the pure USBC headphone is available from
The 6T is also coming with an under display