Insider reports suggest that the OnePlus 8T will be released on October 14. It is likely to be accompanied by the sub-US$200 OnePlus Clover and the OnePlus Watch. OnePlus is yet to officially confirm the date, but we should know for sure in the coming days.
https://www.notebookcheck.net/The-OnePlus-8T-will-allegedly-be-unveiled-on-October-14.494656.0.html