HiFiMAN have worked with Massdrop in the past with great success. The HE-4XX has been incredibly well received, and the latest release sold out within hours. Second-hand examples are snapped up on Head-Fi near instantly.
The HE-6 is a legend in the headphone world. It competed with the HD-800, LCD-3 and other reference cans, and in many people's opinion was best of the best. The discussions regarding how to get the best out of the HE-6 (being notoriously hard to amplify and with an abundance of possible modifications) go on to this day. This is despite it not being manufactured for some time. The HE-6 successor (HE-1000) has not developed anything near the cult following.
I for one would be really keen to see the HE-6 (or other high-end HiFiMAN planars) get the Massdrop treatment. If anyone agrees, let me know!