This is the basis of the ASUS warranty issues recently when they had exploding AM5 motherboards and vague text about EXPO support voiding warranty, painting themselves into a corner when they only had unsupported firmware that would technically void warranty.
It doesn’t matter that the company says “Oh we won’t enforce that rule” but they still keep the rule in place.
Microsoft’s implementation of the feature is called Windows Update Delivery Optimization.
https://support.microsoft.com/en-us/windows/windows-update-delivery-optimization-and-privacy-bf86a244-8f26-a3c7-a137-a43bfbe688e8
Here’s a short optimisation guide: https://www.ctrl.blog/entry/windows-delivery-optimization.html
Fundamentally it’s not like the Bittorrent protocol, even though there are similar behaviours and the result is the same. Microsoft retains the ability to stop the network from seeding updates and has ways of only targeting specific supported configurations to receive new updates.