These days, everyone is so interested in the movies on their iPads, that they close the screens for 99% of the flight anyhow. Fewer/no windows would certainly make for a lighter & stronger fuselage. A series of OLED screens showing the view out the sides may be cheaper, lighter, and easy to implement.
OTOH, there would need to be SOME windows for the flight attendants to look for fire, etc during emergencies. Those in exit rows may be the ones privileged with windows...