In the last week before the OnePlus 6T's release, the leak- and rumor-mill around the device is still going strong. Most recently, a phone with a model number that could correspond to the phone has appeared on Antutu Benchmark. It scored about 10,000 more points than the OnePlus 6.
https://www.notebookcheck.net/OnePlus-6T-s-model-number-shows-up-on-Antutu-scores-higher-than-the-6.346146.0.html