Does anyone remember the covert asicboost drama? and the rumors of them using it indoors? They always denied it, until overt asicboost became real, somehow their S9 models could do it, but not their previous models. So the rumor was proven correct after months of denial...
Wrong. Bitmains covert AB was never used on the main BTC network. That is a very different thing than the chips having the circuits in them but never turned on. BM never said anything about if the chips have AB circuits in them, they just said it was never ran outside of TestNet.
When any sort of AB is used it changes the block version number and NO blocks ever show that change before Dragonmints came online.