Tell me, when was the last time you went to a concert?
Because you should know, it’s very common for someone to talk a little before the concert or before the piece about the piece itself, what inspired it, how it fits into the programme, etc.
That’s what he did here. He explained what inspired the writing of this piece. No different to a conductor explaining that Shostakovich’s 7th Symphony was dedicated to the city of Leningrad, which at the time it was premiered was being besieged by the Nazis. Or explaining how his 9th Symphony was a deliberate mockery of earlier composers’ grand 9th symphonies, as a way to subvert expectations placed on him by Stalin’s regime. Or how Beethoven’s 3rd Symphony was written at first in honour of Napoleon, and then later changed to “celebrate the memory of a great man” after Napoleon went against Beethoven’s republican idealism and crowned himself emperor.
Music has always been political, and in modern times no concert is complete without at least some discussion about the context in which the piece was written. That should be as true for a piece written to commemorate victims of a modern-day war as it is for mid-20th century or early 19th century pieces.