OnePlus just announced a collaboration with Marvel Studios to celebrate its 10th anniversary with Avengers: Infinity War, which arrives in theatres on April 27, 2018. If you remember, OnePlus has partnered with Disney India last year in December 2017 to launch OnePlus 5T Star Wars Limited Edition. This year you can expect the OnePlus 6 Avengers: Infinity War Edition which may be basically the OnePlus 6 with customisation around Avengers: Infinity War theme.
At the moment, the company is yet to officially announce the launch date of OnePlus 6 and hence we are not sure when it will launch officially but the rumors indicate a possible launch in the month of May 2018. We have already seen alleged renders of OnePlus 6 thanks to Olixar cases that revealed the design of OnePlus 6 showing the front notch with a high screen to body ratio and the dual rear camera.