Hi there,
To the best of my knowledge, the 20H2 update has not expired. It will be serviced for 30 months from the release date for devices running Windows 10 Enterprise or Windows 10 Education editions. Like the 1909 update, the Win 10 20H2 is available as an enablement package,
To upgrade to Windows 10 20H2 using ConfigMgr, you can either use the servicing plans or deploy the 20H2 feature update or enablement package. SCCM admins can deploy the Windows 10 20H2 enablement package to upgrade Windows 10 2004 to 20H2.
Hope this resolves your Query !!
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