We found ASICBoost independently in the beginning of 2014. We called it Merkle Collisions and patented it also, but only later. ASICBoost saves about 15% in electricity once you actually implement it in a chip.
If we assume that BitmainTech directly control 500 PH/s (they control less in my estimation) of S9 machines (power efficiency at the wall of about 0.1 J/GH), then assuming they deploy in their data center in Sichuan (sub 0.03 $/KWh), the total annual savings are:
500 / 0.1 X 15% X 24 X 365 X 0.03 X 1,000 ~= $2M
Those numbers are easily verifiable. I believe their claim about not activating ASICBoost. It is very small money for them.