Perhaps gyroscopic is the wrong term scientifically then. Regardless I find that when pedaling out of the saddle on a 16" wheeled bike one needs to retain a firmer grip on the handlebars to keep the bike from tilting right or left as you push down on the right or left pedal respectively. This isn't really a big deal after you've ridden the bike for a few days and have become accustomed to it.

I suppose the rotation of the wheels could be irrelevant and this could just be caused by folding bike generally having a lower center of gravity in part due to small wheels and in part due to the step through frame design.