The above image is a section of the t&c page which mentions 14 October as the last date of the Quiz, and this may be the launch date of the OnePlus 8T. Recent leaks also point to October 14 as the launch date. Now, see the point number 5 in the t&c, it clearly reveals that there will be an 8GB RAM variant.
Past leaks reveals that, the OnePlus 8T will feature a 6.55-inch FullHD+ AMOLED display with 120Hz smooth refresh rate. Leaked render of the device reveals a punch-hole cutout for 32MP front facing camera. On the rear side, it has a quad camera setup which includes a 48MP primary camera, a 16MP ultrawide lens, a 5MP depth sensor and a 2MP portrait lens.
The OnePlus 8T is said to pack 4,500mAh battery and supports 65W fast charging unlike the 30W charging in OnePlus 8. Under the hood, the device will be powered by Snapdragon 865 chipset with integrated 5G modem.