OJB
The angle of attack is due to the direction of the relative airflow, which is a function of the forward speed of the aircraft (TAS) and the strength of the crosswind. Thus higher forward speed = smaller angle of attack change = crosswind has less effect.
OJB,
If you approach with the 'crabbing' technique(i.e. : no sideslip), there is no 'angle of attack' on the fin, just as when you are flying the airway with a lot of crosswind, as in this case you are just 'pointing' the aircraft into the wind, but you do not have the ball/slip indicator displaced sideways (so, no slip).
You have a sideslip (i.e. : an angle of attack on the fin) only when you are approaching with a sideslip.