There's an FAQ somewhere on Apple's site which I ran across awhile back that said something to that effect. The deal to require customers to re-buy lost files was part of how they got all the labels to allow the store to even exist in the first place back in the day. Given that music no longer has DRM, this one remaining concession is probably going to be even harder to get dropped because it's one of the only "protections" that the music store offers to the labels now.