A flash below the lens? That's a big no-no. It forces shadows up, so you can see them, rather than down - especially when a subject is close to a wall or some other object. Also, it illuminates places like under noses and chins, where we are used to seeing shadows. It makes the tops of eye sockets brighter than they should be. That's because we are hard wired to expect light to come from above, such as the sky, and when you flip that around and the light comes from beneath, the lizard part of our brains tell us that something is wrong. Old horror movies like Frankenstein used this technique to cause unease in the audience.
Yes, I know it's a tiny flash beneath a tiny lens and they're very close. The axis of light output will still be beneath the lens when held vertically regardless, and the physics of light doesn't change. There's a reason why even small cameras with small built-in flashes don't put the flash on the bottom of the camera. I hope they are wrong with this rumor.