The UI controls don't look like that in Windows 11 (even on the white theme), and also who actually installs the Bing add-on? (or are they saying that Bing icon thing should now be in Edge as well?).

Again, it's possible they're signed up for insider builds (or dogfooding, or otherwise obtained some branch build of Windows); but with all the latest updates applied to my Windows 11 OS (and Edge) I see nothing like this (so no repro).