Hi,
There is no official deadline, but please note that you can upgrade to Windows 11 for free provided you have a genuine Windows 10 license (whether OEM or retail); however, licenses that originated from Windows 7 or 8/8.1 (and were upgraded to Windows 10) are not eligible for the Windows 11 upgrade.
Regarding tracking, there is no official information available. However, having used Windows 11 myself, I’ve noticed a reduction in the number of ads following the 25H2 and now 26H2 updates, and—importantly—Copilot is becoming optional. In my opinion, Microsoft is working to improve system usability and performance for the end user.
Credits: https://www.microsoft.com/windows/get-windows-11
Please consider rating the question (accepting the answer or not) and visiting the Microsoft Q&A community if you have further questions.
Thanks.