Just like recent leaks claimed, the Google Pixel 4 phones will be launched at an event in New York on October 15. There's not much we don't know about the phones' hardware at this point, so we're a lot more interested in the software Google will showcase at the event.
https://www.notebookcheck.net/Google-Pixel-4-and-4-XL-confirmed-for-October-15-launch.434910.0.html