Yes, I agree these are not particularly revolutionary. Different driver types do not guarantee a better sound, just different qualities.

The Acoustic Metamaterial Tuning System in my opinion is very clever. Although I am not qualified to explain it in detail, eliminating standing waves will certainly reduce interference and allow for a FR more compliant with the Harman Target. If you are not willing to EQ, this seems to be the solution to a near perfect frequency response. In fact, the legendary Axel Grell (he designed the HD600 HD800) had high praise for it.

In my opinion, we have hit a plateau in terms of improving subjective sound quality. There is nothing new that guarantees better sound.

If we want progress we must put research into what we perceive as good sound and try to find physical metrics that are correlated and fine tune the headphones. Personally I don't think the FR and THD tell the whole story, and neither do the manufacturers. I think what's going on right now is that people know what to do to make headphones sound nicer without understanding precisely how it works. If you took a pair of Hifiman Susvara and AKG K361 and measured them, you wouldn't be able to tell one sounds so much better than the other.