https://www.techradar.com/news/oneplus-6t-could-be-announced-on-october-17

We know the OnePlus 6T is coming soon, given that even OnePlus itself has been teasing the phone, but now we may know the exact date of the announcement: October 17.

That dates comes from an image posted on Chinese microblogging site Weibo by someone with the username 'Little white MTX'. The image (which you can see below) appears to show an invitation to the OnePlus 6T launch event in India.