I agree with you on certain points. Yes, a saeculum is most certainly a by-product of various forms of generational interaction. No doubt. I do think a boomer will be elected as the next president, and arguably the last of their generation. I don't think the military body count will be very high during the next global war. Drone tech has made it far too easy to cause mass damage.
It's as Nikola Tesla said:
"The loss of life will become smaller and smaller, and finally, the number of the individuals continuously diminishing, merely machines will meet in a contest without blood shed, the nation's being simply interested, ambitious spectators. When this happy condition is realized, peace will be assured."
And this is exactly what we're seeing now.