The question to Nord could only result in this answer.
Clearly, Nord transitioned to a new architecture with Nord Wave, then with Piano 5 bringing Sample nsmp v4.
After Wave 2 and Stage 4 all pianos share the same reverbs, FX and the “per layer” implementation.
This means, technically (imho, not knowing what DSP chips are at work here) the new Organ engine is just an enhancement to the old engine, mainly the Leslie emulation.
So yes, Electro 6 architecture probably does not allow for an update.
Stage 4 architecture would seem (seem!) possible, but as already mentioned before Nord didn’t give the C2D engine to Stage 2 back in the day. Only Stage 3 received the new engine.
At this day, it seems that the boards share more of the same architecture so maybe Nord will surprise us!
