A device that appears to be the Mi 6X has made a surprise appearance on TENAA. It isn't a full listing, though, so all this tells us is that the device will sport a design similar to the Mi 5X's but with an 18:9 display and vertically aligned dual rear cameras.
https://www.notebookcheck.net/The-Mi-6X-pays-TENAA-an-early-visit.291712.0.html