Alexandra's album actually went up for pre-sale the week after the show finished last year! If you pre-ordered within two weeks you got a special edition, 2 CD album so they got loads of pre-orders from that alone. God knows what number the sales are up to now!
I like Cheryl a lot too and I'm interested to see what she does musically, BUT in my opinion I think releasing it the same day as Alexandra's is very deliberate. If it doesn't get to number one, then it's not exactly a disaster is it?
They can say because it came out during a tough week, and being second to Alexandra isn't that much of a bad thing. I just think they've done it for that reason... so it would look like she could never had a number one album anyway, because of Alex? As I don't believe she'd get a number one album on her own, as much as I like her.