Windows 10 1709 is a rather old version called the Fall Creators Update; it debuted on October 17, 2017. True, the extension of support does not apply to all its variations.

Microsoft has extended support for the old version of Windows 10 due to coronavirus

According to Microsoft, it has extended support for enterprise and educational versions of Enterprise, Education and IoT Enterprise in response to requests from users, many of whom have now switched to remote work. Previously, it was planned that support would end on April 14, and now this period has been shifted to October 13, 2020.