So basically we just won't see a better miner from bitmain for sale until someone comes out with a really good miner in the 0.06 or 0.07 watt per gh area.
But you can't design and produce a new miner overnight. Bitmain will lose truckloads of money if they are reactive like that and let a competitor get ahead for a few months. They do have a mining operation too, so if they are smart they will produce a new more efficient miner asap for themselves. By keeping it internal, they can maximize mining profit, and let the competitors invest in an "S9 killer". As soon as competitors start trying to sell their miner, the S11 batch comes out for sale, what a kill 
I'm not saying they'll do this, just that it looks like a better move than sitting on their hands and waiting to be hunted down. Now that I read your message again I see you didn't say they won't produce it, you say we won't see it, do you agree they may do what I think?