It is a moving and inspiring story. It's genuinely touching that the bond between these men continued to exist for over six decades and in this gesture will have a symbolic resonance permanently.
What I must say I do find distasteful is that you seem to have taken the inspirational emotion of the story and used it to conjur up some kind of 'everything was better in the 40s' sentiment.
Frankly, I hope my generation (the one you're implicitly slagging off) never has to face an experience like those faced by these men. While the story is a powerful and poignant reminder of the sacrifice made by those who died in the various C20 wars, it's also a reminder of how tragic it was.
To answer your question, looking at the people of my own generation around me, I do believe that if there was a WW2-style total war situation (which there isn't, let's be very clear on that), I imagine that plenty would still willingly go and fight (if we ignore conscription for a moment) - you might get a bit more that wouldn't than you did before, but that's because things like pacifism and opposition often come from more education (which seems a fair price to pay , I think)