Again, it's simple.
For example, if a wing falls off an aircraft in flight, is it then incapable of flight? Yes, it is.
In this case, if a 737Max experiences an AOA malfunction that triggers an MCAS activation is there any aircraft related reason the aircraft is incapable of maintaining flight?
Semp, I am not positing any unusual situation where the crew is not at duty stations. It's simple: can the aircraft still fly? Are all the systems that allow an aircraft to maintain flight still available and operational? Yes, there is what we call an ABNORMAL in progress but that is all.
Fess, can an aircraft fly without AOA indications? Without an AOA disagreement light? (BTW, the Ethiopian pilots DID NOT follow the Boeing guidelines. Unless you think never reducing power from takeoff thrust and overspeeding the aircraft in a steep climb and turning the Stab Trim Cutout switches back on is Boeing guidelines.)
Sure, without MCAS the flight could have been made safely.
Now to you Fess: Had the MCAS system been correctly disabled after the AOA malfunction, would Lion/Ethiopian have made a safe return?