These are my thoughts....
LV probably works at the venue on the admin side where he can see what's booked when. He is informed that the show has been moved. He asks if other shows are being moved and is told yes. He also knows what the ticket sales were like.
He puts 2 and 2 together and announces his theory here.
Is he an Insider? No. Is he someone who knew info about 3 milliseconds before the rest of us? Yes.
Real insiders know when to speak and when not to, otherwise they don't stay insiders, I think. And no, I'm not one either