I actually completely forgot about that - but you're also right that it's a charity and not some war fund. It could be argued that this record is not so much stoking the fires, but more picking up the pieces for those affected by the aftermath. I don't know though, the tune sounds more like a battle cry than anything else. Something you'd play to charge up the troops, so to speak?
And yes, this does seem more like a personal rather than ideological decision on Gilmour's part.