Microsoft is moving from 10 year to 5 year lifecycle support plans which are designed to keep customers more on the latest product versions.  And this is to sync with M/365 support also.  The latest versions are often more secure but will require a little more cost/work for organizations to stay on supported versions.

Microsoft To Cut 5 Years of Support from Next Windows 10 and Office LTSC Products —

Microsoft this week announced it will lop off five years of support when it releases the next Windows 10 long-term servicing channel (LTSC) product and the next Microsoft Office LTSC product, both of which are expected to arrive in the second half of this year.  Those five-year support cuts are being done to align the two products’ lifecycles, claimed Joe Lurie, a senior product manager for Microsoft 365, in a Thursday announcement.

Today we are announcing that the next version of Windows 10 Enterprise LTSC and Windows 10 IoT Enterprise LTSC will be released in the second half (H2) of calendar year 2021. Windows 10 Client LTSC will change to a 5-year lifecycle, aligning with the changes to the next perpetual version of Office. This change addresses the needs of the same regulated and restricted scenarios and devices.