The pitch changes with flaps, flaperons, spoilers, and spoilerons are essentually "random" in sport models. I've never seen anyone able to predict 100% which way a particular airplane will go when something is deployed, at least by eyeball looking at a plane.

Factors that I KNOW change the pitching tendancy of an airplane include (but aren't limited to) (and, in no particular order):

- tail moment. Longer tail moment planes tend to pitch up with flap, but with a short tail moment, you start to ack more like elevons, and you pitch down. (flying wings are the extreme of "short tail moment", as are many combat planes)
- CG location. If the CG is more aft, the tail isn't working has hard. If the CG is back enough, the tail starts to lift "up" rather than down. This means that messing with the airflow over the tail can cause either pitch up or pitch down, depending on your CG location!
- Size, shape, and location of device. Due to changes to airflow over the tail, and weither you are creating or destroying lift, how much lift, and where on the wing the lift is changing.
- Angle of deflection. I've seen planes where a little flap caused nose up due to increase in lift. But lots of flap caused nose down, probibly due to a combination of drag and "elevon" effect, though I'm not 100% sure exactly why.
- Airfoil. Differnet airfoils have differnet pitching moments. Changing the TE of the airfoil often changes the pitching moment. That might or might not cause the tail to have to provide more or less lift to balance it out.
- AOA. dropping flaps increases the AOA of the wing. Espeically with very small flap movements, this can change the lift, but you can also actually stall part of the wing this way.

Also, keep in mind that there is often a momentary or trasient pitch change, and a possibly differnet long term pitch change. It's quite possible to have a situation where if you dropped flaps (or raise spoilerons), the plane will balloon upwards (or downwards), with a quick pitch change. But after a couple of seconds, it might stabalize out, and there could be a net trim change effect that could go in the opposite direction. So you might get a momentary pitch in one direction, and a long term trim change in the other. Or in the same direction, but to a different degree. Often deploying the flaps/spoilers in a slower manner, and at slower airspeeds, avoids overly dramatic transients.