I think they are more concerned with extended two pilot ops, where one pilot is left alone on the flight deck while the other one rests during long haul ops which currently require crew augmentation.

True single pilot ops, with today's airplanes, is a complete non-starter due to loss of PM and the fact that if the solo pilot becomes incapacitated the plane will most likely crash, unless the FAs realize what happened quickly enough, access the flight deck, and find an off duty airline pilot in the cabin.