Had this happened in 1919, I think it would have been forgotten already, as it would seem pale compared to WW1. In 1912, people were quite innocent, so this was seen as a big event.
Was WW1, at least in part, something that was allowed to happen before most people had forgotten earlier big wars? Roughly 100 years had passed since Napoleon, after all.
When authors today again consider Titantic to be "unthinkable", what does it mean?
I consider it perfectly thinkable that something in our lifetime will trigger a nuclear war, killing billions of people.
Especially if we start to take global stability for granted.