In general yes, I'd expect it to remain stable. The RHP zero frequency should increase at light load, and as your controller starts operating in DCM, its gain should decrease. Those two things should only increase stability (unless the system was only conditionally stable). The only thing it could worsen is the damping of your LC, which might cause some extra phase lag, but it's unlikely to be enough to overcome the loss of gain and cause instability.
Is this still the same issue as in your other thread? Based on what you explained over there, it sounded like it must be a relaxation oscillation, not a small signal instability. Did you notice that the amplitude or frequency of the ripple changes depending on the load impedance?