The functionality is available today for Windows Insider participants. It should be available to all Windows 11 users sometime in November.
The news comes just as the Apple Music app launches on Xbox consoles. It reflects Microsoft's ambition to make Windows the "most open" desktop platform with support for rival services and apps. You can use Android apps and run Linux instances, for example. While this is partly a not-so-subtle dig at Apple's more closed ecosystem, it's good news for users who'd rather not switch hardware just to get seamless photo syncing.