Is it possible to upgrade to Windows 10 now the deadline has passed?

Yes!

If you use assistive technologies, you can get a free upgrade to Windows 10 as Microsoft continues our efforts to improve the Windows 10 experience for people who use these technologies.

https://www.microsoft.com/en-us/accessibility/windows10upgrade?tduid=(14c348e893a91089cb2980533c6ee123)(256380)(2459594)(TnL5HPStwNw-0FBZfNm6YPFXNhiu3o52rA)()