Quote Originally Posted by Windows Central
[...] Recently, we saw evidence that Microsoft is gearing up to lift this restriction on Xbox Live, allowing you to have multiple points of presence across different devices and platforms.

You'll still only be able to launch games on one device at a time using your account, but this new system means that you'll be able to play the best Xbox One games via cloud streaming on your phone, without being signed out of your consoles. This means you'll be able to continue using streaming apps and services like Netflix, YouTube, Disney+, or Microsoft's own Movies & TV on the same account, while using Project xCloud on your phone. [...]
Xbox users will soon be able to sign into multiple devices simultaneously