Plan for the worst, hope for the best. Portisch has said CE-NG is EOL a few times since then. There’s no CE-NG 22 development on github. Whether that changes or not, nobody buying a s922x/z now should expect any updates after CE-NG 21.
In the context of CE, the Cube and AM6+ have identical SOCs, and SOC features like video & audio playback are also identical. TV-LED DV, yes.
Storage can be moved to the eMMC on any CE device, Cube included. The difference is that this still requires booting from USB, but CE is almost entirely running from RAM+eMMC.
Read about limitations & requirements here. The limitations can either be cheaply supplemented, or arguably don’t matter for typical CE use.