Comment by tialaramex

I think that would have been an alternate present rather than a plausible future.

ECH needs for the outer (unencrypted) SNI to be somewhat plausible as a destination. For ECH GREASE what happens is that this outer SNI was real, what looks like the encrypted inner ECH data is just random noise.

For non-GREASE ECH we want to look as much like the GREASE as we can, except that it's not noise that's the encrypted payload with a real inner SNI among other things.