The End of Life Detection of a Operating System heavily depends on the detail grade the OS was detected during the scan.
As an example the extended support of Windows 7 with an installed SP1 ends in January 2020 so a Windows 7 can’t be reported generally as End Of Life because it isn’t if SP1 installed.
If it was not possible to detect if a SP is installed on the target no EOL message will be reported.
Have a look at the output of the following two VTs how and in which detail the OS was detected:
OS Detection Consolidation and Reporting (OID: 220.127.116.11.4.1.25618.104.22.168937)
Unknown OS and Service Banner Reporting (OID: 22.214.171.124.4.1.256126.96.36.199441)
You also might want to consider to configure Authenticated Scans against your Windows.