One of the things I never understood about de-aerated sparge water is doesn't the water just pick up that aeration again duding the sparge? I understand hot liquids don't take up o2 as readily but still. Maybe this has been answered somewhere and i missed it.
As far as modern brewhouses go, unless a brewery is recycling/capturing their Co2 (from fermentation)I can't believe anyone could afford to mill under co2 without an incredibly advanced and expensive mill. Wet milling I get, but the the liberal use of Co2 on some of these applications I can't fathom. Yeah, co2 is cheap. Sorta. Kinda. But not really.