Correct, but can only be achieved after the rider gains a sufficient strength and endurance in the propulsion department. Requires riding with a certain minimum intensity.
Until then, most riders which are new to cycling or are making a re-entry - or are impeded in any way - are unable to absorb any significant body weight with their legs, and that leaves the majority of the weight borne by the saddle. I've observed this on multiple occasions, and am sure you have as well...