Let me qualify myself, I am an Aerospace engineer and a practicing aerodynamicist.

The effect is completely dependent on how the raising of the ailerons changes the flow on the tail. If the ailerons are well outboard and they do not change the flow on the tail you will pitch up. If they do change the flow on the tail it could be anything from pitch up, to do nothing, to pitch down. It can be calculated, but it is sort of complicated. You have to calculate the change in the down wash of the wing at the tail.

Raising the aileron makes the wing generate a larger nose up moment. If the aileron is in front of the tail raising it will increase the angle of attack of the tail, which in turn creates a more nose down moment (in reality it is a smaller nose up moment). It all comes down to which moment is bigger. If the change in the wings moment is larger you pitch up, if the tails moment is bigger you pitch down, if they are about the same nothing happens.

Steven