Yes. If the tires are hard enough that the entire bike is getting vertically deflected by surface irregularities, the energy that becomes that deflection is coming from your forward momentum.

High-performance tires simply don't lose that much energy from being deformed against the ground as they roll, so if you're running fast tires at super-high pressures, the energy wasted buzzing the bike and rider can easily exceed what you're saving by making the tire stiff.
Since pumping a tire softer can also have comfort and handling benefits, erring on the squishy side is not a bad idea,