A new leak, reportedly originating from Weibo, consists of (remarkably grainy) images of a retail box that bears a close resemblance to those used for OnePlus phones in the past. This box also bears a '6T' logo and is lined with text related to the OnePlus Community forums.
https://www.notebookcheck.net/Oneplus-6T-New-leak-claims-to-show-retail-packaging.328870.0.html