Although the new XPS 15 2-in-1 (9575) was supposed to begin shipping more than a week ago, Frank Azor has just confirmed that many early adopters still have to receive their machines due to a delay that has been caused by "a small bad batch of the Mag lev keyboard." Even more, the i9 processor upgrade is not available yet but will be added on May 10.
https://www.notebookcheck.net/Frank-Azor-The-Dell-XPS-15-2-in-1-9575-was-delayed-due-to-the-the-mag-lev-keyboard.301550.0.html