Dinesh Dave, a former Apple engineer, posted a post on Twitter, stating that his last NDA (non-disclosure agreement) product, AirPods Max, was finally launched. After the post came out, someone calculated that AirPods Max took 4 years to develop. And Dinesh Dave also deleted the post soon.
The news about the high-end version of AirPods was first revealed by analyst Guo Mingchi in early 2018 . After that, news of the postponement of the project continued to spread until December 2020 when this high-end headset was finally available.