The Garmin Descent Mk2 series is based on the Fenix 6 series, same basic hardware and software but with the addition of a more water-resistant case, depth sensor, and dive computer software. Just like the Descent Mk1 was based on the Fenix 5. Garmin recently launched the Fenix 7 series so they will probably have a Descent Mk3 available sometime in 2023. When that Descent Mk3 shows up it will of course include all the new fitness and health metrics from the Fenix 7. Possibly it will also have a brighter, higher-resolution AMOLED display (like the Epix 2) but I wouldn't count on that. I doubt they will make any major changes to the dive software although I guess it's possible they could add a different deco algorithm like VPM-B.