Thank you for confirming this.My bridge is on the same SW version.
From my understanding, yes any device on iOS 15 will no longer be able to control the Home.
I've had a heck of a time with compatibility of the Hue App, Bridge and Mesh routers to achieve out of home control with Internet LED always blinking. Controlling from iOS Home always worked though. Well, since current Bridge update it finally all works so this, plus my old SE then not functioning is giving me thought to leave as is.
Are you seeing any benefits after having upgraded?