We've known for a number of years that Microsoft has been experimenting with dual-screen devices. The first was the Courier concept, then there was the Andromeda project (aka Surface Phone) which is said was put on hold. Those dreams, however, look like they might coming fruition in the form of a foldable Surface device that can also incorporates a cellular connection.
https://www.notebookcheck.net/Foldable-MS-Surface-with-9-inch-display-Android-app-support-Intel-Lakefield-10nm-SoC-coming-2020.425365.0.html