We'd still have the debate, but if we know in advance that we're going to show or describe the horrors of war in graphic detail, we'd warn the veterans in the audience beforehand. Trigger warnings aren't censorship, they're common courtesy.
How long before the trigger warning itself triggers the very behavior they're trying to warn about?
So i am not courteous and now what?
Are you not paying attention? Trigger warnings are how you can have public debate without triggering people.