Windows 10 21H1 will be available for every people in the upcoming April. So far as Windows 10 21H2, the foundation of this version will be ready with several changes in June. Dev channel is running on 21343 and today Windows 10 build 21350 or 21349 will be rolled out.
Microsoft is going to split the versions of the Cobalt series which includes Sun Valley project and start with 2201. Our colleague’s site Deskmodder has explored that the language package version 223188.8.131.52 appeared as an update through the Microsoft Store.
Language Pack 22350 appeared in Microsoft Store
So the new language pack surprising version does not indicate that you will need to switch to the new version in the dev channel straight away. But you will be offered 21H1 until December as an optional update. Microsoft is already making the split ready internally.
1] Windows 10 21H2 Version – Full list of Features of Sun valley update
2] Windows 10 version 21H1 Feature update Changes, Improvements, Bug Fixes
3] Windows 10 2009 20H2 All Features, Improvements, and Changes
Source – Deskmodder.