Windows 10 finally reached its end of support on October 14, 2025. Originally the impact of this deadline meant that running the Microsoft 365 Apps on it would not be supported. This would have affected the two types of updates available for the Microsoft 365 Apps: feature updates for functionality and performance improvements, and the separate security updates for critical patches and bug fixes. Microsoft have since announced an extension on both, with feature updates continuing up to January 12, 2027 (depending on your chosen update channel), and security updates continuing until October 10, 2028.

You can find full details here: http://bit.ly/4qaDXqK.