I just had my app rejected because I mentioned pre-release software or hardware in the metadata. It doesn't say what it is that they consider pre-release so I have assumed that it was the mention of compatibility with the iPhone XR, which was released today. I have changed that to say "latest iPhones" and re-submitted it.
However this is just a guess. It could be because I mentioned the Apple Watch Series 4 which is not available in some countries yet. If so then I should probably pull the app and take that out of the description, but the whole point of this release is compatibility with the series 4.
I was wondering if anyone knew what I could be mentioning that is still pre-release? As far as I know there isn't anything that has been announced but hasn't been released somewhere.
I really wish Apple would be more specific with their reasons for rejection.