I don't know anything about photography, but if moving the flash provides a better picture, hooray for us all.
Yes, it will reduce red-eye and offer slightly more apparent "depth".
The thing is: the "best" place (from a camera's perspective) for the flash is
as far from the lens as possible. That would be the opposite corner (lower-right when viewing the phone from the back with the camera at upper-left).
Unfortunately, the ergonomics don't work as well, even in "traditional" point-and-shoots, so the flash tends to be along the "top" edge of the device. It's a trade-off: more red eye tendency, but fewer failed photos where your index finger is obscuring the flash.
That having been said, being "in line" with the lens horizontally will lead to an "artificial" lighting look, so while there will be more depth cues, it will still look very plastic to most eyes. Unless, I suppose, you tilt the camera at a jaunty angle to get the flash off-axis, then straighten the image in post.
Also, while the minor flash displacement will allow for some depth in really-close-up photos (which are probably going to be washed out even with this change unless Apple has a multi-level flash to give a less powerful burst for close-up photos), for anything more than a few feet away the flash and lens are still so close together that they might as well be directly side-by-side.
The physics of cameras are rather well understood. There's not a whole lot to be invented in terms of flash placement. I'm sure Apple knows what it is doing here and is going to get the best flash photography out of the iPhone that they can, but you shouldn't expect this move to be a night-and-day fix for all the flaws of iPhone flash photography.
