The resultant AOA from the forward momentum of the aircraft and the vertical component of the strong updraft, increased the lift and moved the center of lift forward on the swept wing, mechanically pulling the nose up. (Overpowering the tail plane force.) The resultant pitch-up attitude depends on the strength of the vertical updraft and the length of the moment arm, from the c.g. to the tail plane.
I'm sorry, but this just does not make sense. Somehow, we are to believe that an aeroplane can be pitched up 25 degrees caught in a violent updraft, and still maintain altitude? If an aerodynamicist can confirm this I will believe it, but what you say above does not make sense.
A sudden updraft has a similar AoA effect of instantaneously pitching an aeroplane nose up. Stability is designed into aeroplanes whereby they will restore, and the tailplane will provide a nose down effect.
I repeat, the only way this makes sense (nose up and maintaining altitude) is if you are in a sustained downdraft.