Apple has confirmed when the Watch Series 7 will be available to pre-order and in which countries. The Watch Series 7 will start shipping a week after Apple opens its pre-order window. Someone has already published hands-on photos of their Watch Series 7, though.
https://www.notebookcheck.net/Apple-Watch-Series-7-pre-orders-to-open-this-week-in-over-60-countries-as-hands-on-images-leak.568933.0.html