They'll have to setup some type of "remote Copilot" system. No way the FAA will allow single pilot even for cargo unless there's a way to get the jet back on the ground with an incapacitated pilot.
A few aircraft, mostly single engine turboprops have a emergency recovery button for pax to push in case of an incapacitated pilot. But these aircraft only require one pilot.
And what happens if you need to go take a dump during the flight? Are the pilots just going to wear diapers?
It'll take years and years to design and certify a "remote Copilot" system where a single Copilot covers several flights at one time.