If the rumour is accurate, we might see Windows 10X in the first half of 2021 and then Windows 10 21H1/21H2.
Rumours suggested that Microsoft may end up releasing just one feature update in 2021 to make room for Windows 10X, a modular version of Windows 10. Windows 10 version 21H1, also known as ‘Iron’ update’, was originally supposed to be the first major Spring 2021 update, but the plans have reportedly changed after Microsoft decided to focus on Windows 10X for single-screen devices.
According to reports and references found within the preview builds, Microsoft is currently working on Windows 10 21H1, Windows 10X, and Windows 10 21H2 “Sun Valley” update.