The physics aside, you know that more than like the change to Lightning's bust size has been in for a while and no one noticed until they mentioned it. If the developers never said anything you never would have known. Any changes you thought you noticed would have been chalked up to either outfits appearance or just that you remembered differently.

Granted, I'm not really fan that they did it just so that she made the outfits they put her in look better. It's aesthetics, but still design better outfits and you wouldn't need to. A lot of the outfits appeal to different fetishes people have. So I think they're trying to hit everyone's tastes, not a fan of a lot of the more revealing items.

As an aside, I mentioned this in one of my last new posts. ^^