For the unawares, Windows OEM are operating systems sold to manufacturers to install on prebuilt computers and are often customized to the manufacturer's standards. This allows them to make operating systems that only work on some devices and some devices that only work with certain operating systems, in other words just another way to bleed their customers for more money and reduce repairability and maintainability.

The flipside was probably that the OEM had different EOL dates and Microsoft is planning to try to cut it short.

My distribution's licensing fees also went up that percentage recently, so it's understandable

That's a 42% increase in price. Did Windows get 42% better when I wasn't looking?