Had a good interaction with technical support. The full testing and support for Windows 11 is still in progress. Should be ready in a few months. I can still get support with issues if I install updated Windows 11 drivers from manufacturers' sites (such as Intel). I am OK with this for now.  
Windows 11 installed on just delivered new XPS 8950. When I go to Support, Drivers and Downloads, Manually apply, Windows 11 does not show up as supported operating system. Only systems listed are Windows 10 and Windows 10S. I contacted support. They said it will be a year before Windows 11 will show up under Drivers and Downloads!
XPS 8950 - Windows 11 not yet supported in drivers and downloads