they would probably just get a different license for the windows
You never tried to license Windows Embedded products, right? Because it's a quagmire of a process that requires signing your soul away and whatnot. In an ideal world, you could just go to a webpage, enter your CC number, and get back a number of licenses/entitlements. But no, Microsoft had to make it hard for everyone.
The fucked-up-ness of Windows Embedded licensing is why at work we spend extra money to run our stuff on off-the-shelf Windows Embedded controllers - we simply don't want to deal with the licensing. It's also why we'll be dropping Windows Embedded in the next two months, as we near the end of testing for the Linux port of our solution. It's utterly infeasible for small vendors (say 100 devices) to deal with Microsoft licensing mess unless they have got way more patience than I do. It's as if the 90s called and wanted their "talk to your distributor" shit back.