Lu, complete bo**ocks on two counts.
1. Having initiated a change in pitch cyclicly by pushing the cyclic that tilts the swash plate etc. the blades as they flap are seeking to recover the equal AoA they had before the cyclic pitch was applied. If cyclic pitch is removed then the AoA is reduced and the blade flaps down - in flapping down it increases the AOA back towards the original value. THIS IS FLAPPING TO EQUALITY - the equality is that of AoA. The disc assumes its new position with the tip path plane tilted forwards and stays in this new plane until something else (that is a gust or another control input and not the preaceesion fairy) changes the equality of lift(AOA) around the disc..
Moving into forward flight produces dissymmetry of lift because the advancing blade sees a change in rotational velocity which causes and increase in AoA - on the retreating side the opposite is happening - guess what... the advancing side flaps up with a high point at the front and the retreating blade flaps down with a low point at the back ----THIS IS FLAPBACK and is a result of flapping to equality. The pilot overcomes this with forward cyclic -something you can do in a helicopter but not in an autogyro - that is the difference.
2. Retreating Blade Stall - continuing from the above argument - as the forward speed is increased so the difference in AoA between advancing and retreating blades increases and to equalise the AoA the retreating blade has to flap down more and more as it's rotational speed is least. Eventually it reaches its stalling angle, has a rapid increase in drag and decrease in lift and flaps down. The effect is most pronounced due to the max rate of flapping between the 9:00 and 7:00 position so when lift is lost the aircraft pitches up and rolls left - THAT IS RETREATING BLADE STALL.
PS apparently one degree of cyclic pitch change produces about one degree of flapping.