tvOS 15 didn't get much attention during yesterday's WWDC 2021 keynote. This is probably because the innovations are very limited. But now a new feature has been announced in a WWDC session.
Like in a new WWDC session As highlighted, a new feature coming with tvOS 15 will make it easier for users to sign in to tvOS apps using Touch ID and Face ID. In tvOS 15, a new system sign-in view gives users a consistent sign-in experience across all apps. This allows users to sign in to tvOS apps using their iPhone and iPad using Face ID or Touch ID.
tvOS 15 uses iCloud keychain information
As shown in the screenshot, the new tvOS login screen shows the option to “Sign in with an Apple device.” When users choose this option, a notification is sent to the nearby iPhone or iPad.

This notification uses iCloud Keychain information to automatically suggest the correct login information. For example, if you try to log into Netflix, the notification will intelligently select your Netflix login information. Of course, it remains to be seen whether the individual third-party tvOS applications will actually adopt the feature at some point. (Photo by Unsplash / Brandon Romanchuk)