Lenovo is looking to redeem itself with a true flagship smartphone after the Z5 debacle and will be announcing it on November 1. This is as official as it gets because it comes for the company's vice president.
In a Weibo post, Chang Cheng published a teaser poster confirming the slide-out camera mechanism and a full-screen display. The sketch is accompanied by Lenovo's mobile division new slogan.

The Lenovo Z5 Pro is still one big mystery - the only solid intel we have on the handset is its quad-camera setup on the back capable of 2x telephoto zoom and a few camera samplespublished by the vice president.
Source (in Chinese)