More details have emerged about Microsoft moving back the RTM timelines for Windows 10 20H1 and 20H2 updates. It seems that Windows 10 feature updates and Azure development and release schedules will match going forward.
This is why Microsoft started early on Windows 10 20H1 development and insiders started getting the preview builds early. So, Windows 10 20H1 update will RTM in December 2019, 3 months earlier than the previous schedules for April updates.
Similarly Windows 10 20H2 will now RTM in June 2020, again 3 months earlier than the previous schedule for October updates. We may start getting Windows 10 20H2 preview builds in Skip Ahead soon.
Future updates like Windows 10 21H1, 21H2 and further will follow this new schedule of Decmeber and June RTMs. Though it still needs to seen whether this RTM will be followed by a sooner public release of the public release will still happen in April and October.
Windows 10X, the new Windows that may power both foldable or dual-screen and traditonal laptops, as the recent leaks suggest, will be pre-loaded onto foldable devices in June 2020, when it will RTM too. The initial assumption of Windows 10X RTMing with 20H1 is discarded witn this new info.