For those of you who use pretty much any of the streaming apps that stream LIVE content via CarPlay(SiriusXM, iHeartRadio, TuneIn). This update makes app’s CarPlay FUNCTIONAL again.
Before this update, they would all fail to connect on first try and have extremely limited functionality if any at all(iHeartRadio was a complete blank screen).
So they are now functioning again, albeit, with the bugs that existed pre iOS 15.