With the cumulative updates of Windows 10 for March 2021, Microsoft seems to have caused utter chaos as many users have run into serious problems.
In the meantime, It seems that the second update of Windows 10 who came to fix the first has ceased to be available from the company.
Have the updates been withdrawn?
On the Windows 10 status page I could not find anything about the revoked 20H2 updates.
Also, the english information page of Windows 10 does not contain information about the KB5001649 update and that it has been withdrawn. A check in the Microsoft Update Catalog showed that update KB5001649 is still available for download.
However KB5001649 no longer appears via the Windows Update GUI on any of the computers I have in version 20H2. If you are interested in it you will find it only through the Microsoft Update Catalog.
At the moment it seems that the cumulative security updates for March 2021 and for the Surface Laptop 2 have been withdrawn.