I think you're wrong in this one. I think the broadcast was a correcting mechanism of the Wheel to end the "false-Dragons times" by showing to the world the one and only Dragon.

Besides "What better way is there to bolster the good guys and send fear into the hearts of the bad guys". This is impossible, as the Wheel doesn't pick sides, it's neutral. "Showing off" would imply that the Wheel is on the Light's side and that isn't true.

And my very personal opinion. No reason. It's an epic scene that RJ wanted to write and we all enjoyed SO much (at least it's one of my favourites). Maybe it's true that it was a "Pattern Level Event" in the sense of correcting mechanism but I think that's just an excuse for the too demanding fans xD

If you think about it, there's no reason for the armies to win/lose depending on Rand's fight either. The Seanchan aren't creatures of the Shadow, they're just being manipulated to some extent. And RJ has shown us more times that a war isn't all about one person. Rand winning doesn't mean the seanchan losing (I'm talking about this specific moment in Falme). It's just symbolism, great symbolism and epicness. Just that.

Happy Birthday, Dragonmount!

I bought the first book in 2009, when I was 17. In these past three years I've read it whole 5 times (except for tGS and ToM, only 3 and 2 times). Actually, I'm re-reading it now. I'm on the 17th book (or 11th depending on edition), so soon enough I will have read it 6, 4, and 3 times xD