Considering the locked flight deck door alone, I would say that there has a been a slight increase in safety (at much cost to plain old enjoyment of flying and chatting to cabin crew and pax).
I reckon attempted hijackings are more likely than severe pilot incapacitation, ie, having a fit/slumped over controls. Now that properly reinforced flight deck doors are being introduced, along with CCTV and remotely controlled locks, it is much harder for a terrorist to gain access and easier for the fit pilot to open the door without getting out of his seat.
As for EgyptAir etc, you're never going to eliminate that, tweezers in the flight deck or not.