The part number for the lighting/turn indicator stalk is 8614A267. The attached pic is hard to see but the turn signal mechanism is on the right and the part is used in all Mitsubishi's by the part reading. There are no pins visible protruding into the central opening of the steering column switch where the steering column inserts into the switch. The removal process simply mentions opening a locking clamp (covered by the tag in this pic) and releasing a locking clamp/pin from the mating groove in the steering column, which would ensure the switch is centred on the column assembly, and sliding it backwards off the column assembly. This locking clip is top centre (accessed from the rear near the dash display) of the steering switch away from the turn switch.
The stalk itself in the workshop manual drawing shows no protrusions on the lighting stalk (3) base into the mechanism of the steering column switch (4) in the line drawing. Given the thickness of the steering column switch itself (as seen in the first pic) and the surrounding plastics one would expect the service drawing to accurately depict any detent pin that would be activated by any mechanical cancel motion. The installation process does not make any mention of taking care to ensure correct insertion of any mechanical cancel mechanism into the steering column switch when installing the lighting stalk. So, my money is on an electrical connection not mechanical. The lighting switch itself looks to be clipped into the steering column switch using tabs at the bottom and then secured by a single bolt tightened to the displayed torque setting.
Having said all this it is possible that the steering column switch contains a pickup which is activated by the steering column during rotation through magnetic flux (like that used in 2 strokes to generate the spark) or the like that sends an electric pulse to the active turn signal and a central solenoid or such releases the lever from its spring tension back to the central off position. The only way to tell for sure would be to see the actual stalk removed from the vehicles steering column switch. I can't find any on my search of the IoT and most sites selling the part just show the Mitsubishi part label and no other info.