Earlier in the year, Microsoft said that it would end support for Office apps and the Microsoft 365 Suite for Windows 10 on 14 October if this year. It seems like there has been a change of heart, as the company now says that support has been extended to October of 2028 instead.
The initial end date of 14 October was chosen as it coincides with the end of support for Windows 10 itself, though you could pay to get extended security updates. Now though, the company says that security updates for Microsoft 365 Apps on Windows 10 will continue for another three years “to help maintain security while you transition to Windows 11”.

On one hand, there are two support articles mentioning this extension. One was updated some time last week, while The Verge reports that another was put up in April for IT admins. The latter notes that while Microsoft 365 will “continue to function as before”, the company still urges businesses to upgrade from Windows 10 to Windows 11 “to avoid performance and reliability issues over time”.
Of course, the other option is, as mentioned above, to pay for extended security updates. But that is ultimately delaying the inevitable, and those making use of the Office suite on Windows 10 should only be using that if you need more time transitioning to Windows 11.
(Source: Microsoft [1], [2] via The Verge)