https://www.techradar.com/news/intel-9th-generation-coffee-lake-s-processors-may-be-closer-than-we-thought

Intel Core i7-9700K and i9-9900K processors have showed up for preorder on European retailers, fueling speculation that the release is right around the corner. 

We previously reported on a leaked Intel roadmap which pointed to the Core i5, i7 and i9 Coffee Lake-S models launching on October 1. CentralPoint, the retailer that posted the early pre-order (and has since taken it down), said that it would be getting stock on September 7, as reported by Wccftech. If this is true, it would seem to back up that October 1 release date.