So umm... Could you technically pirate these updates? Someone could just nab the installer files and share them publicly. I find it hard to imagine that Microsoft built countermeasures for OS update-piracy.
People will probably just post a Powershell script on Github to make it update directly from the official servers without paying the extra fee. It's funny how the most popular activation scripts are on Github, even though Microsoft owns Github and could easily just delete them.
That's what some third parties do for ancient OSes that can no longer use Windows Update but where people want to at least have the last patches made for it, like when people make retro machines. There's an installer package out there that will apply every Windows 98 update ever released in one go. Same for XP I think.