I think in this case, incidence is meant as the angle between the chord-line and the longitudinal axis.
This is important if, as I suspect, they use the term "Super-stall" to mean what is also called "Deep stall".
This was a problem with some T-tailed aircraft (they lost a Trident in test flying due to it) as turbulent flow from a stalled wind would, at certain angles-of-attack, interfere with the tail and render the elevators ineffective, thus leaving the pilot with no way of recovering.
Changing the incidence of the wing would change the path of the turbulent flow, thus altering the tendency for this to happen.