Just got this as well, it’s a bug. I uploaded the near exact same binary as I did a couple of days ago which went through fine (only change was to the version and build number). Developer support confirmed this.
If you do get the e-mail, don’t worry about it. Your binary will still process and you’ll still be able to submit it to the app store.
Update: both of my binaries which received this message passed review and have been released to the app store.