I think it's just common sense to occasionally activate any type of mechanism. If for no other reason than to let you know it's working and not seized.
Sometime you may have to leave quickly, it's nice to know you can retract the slide without any problems.
But that's just me. I know some people think that if your car, generator, snow blower, or anything mechanical is working when you put it in the garage it will work normally after sitting for a year or two.
The few minutes it takes to activate the slide may save you from grief in the future.
