Volume
AoA in my book relates to the angle between chord line of the the wing and the relative airflow (wind).
When you say
Correct. Using only trailing edge devices (flaps) the AoA corresponding to CL max is decreasing. Looking at the old propeller transport aircraft (DC-6, Lockheed Constellation) during approach you can notice the nose down attitude of the aircraft. With zero AoA you are already very close to stall with full flaps.
it appears to me you are talking about deck angle.
Show me a reputable text that goes remotely close to stating
With zero AoA you are already very close to stall with full flaps
When flaps are lowered, the chord line changes, it is lowered at the trailing edge, so even though the deck angle is reduced the AoA hasn't decreased. If I was any good with diagrams I would draw some and post them here to show what I mean.
I would recommend "Mechanics of Flight" by A C Kermode as an easy to read and understand text which covers a wide range of topics like this one.