I understand that, but they said they were waiting for a higher memory variant M6, which was not planned. If they need higher RAM they can go M5 Pro/Max (outside of iMac form factor) or wait hopefully for newer iMac Pro variants in the future.

To be honest, I doubt we're going to see iMacs with very high RAM any time soon. RAM is expensive and most people buying high-RAM machines want to bring their own monitor, not get an all-in-one with a small-ish screen.