There's something you need to understand: Regardless of whatever Microsoft does, Brother doesn't support your printer on Windows 10.
That means Brother hasn't updated the driver in 7 years to keep up with all the new technology in Windows, and they haven't tested the existing driver to see if it works properly in Windows 10 as-is.
So Brother really doesn't know if your printer will work properly now or in the future, and if your printer doesn't work well, Brother has no solutions for you.
This is not something Microsoft can fix, because Microsoft doesn't have access to Brother's software code, and even if they did have access to the code, that's Brother's intellectual property that Microsoft has no right to change. The Brother drivers that shipped with Windows came from Brother, not from Microsoft.
When hardware loses support, that doesn't mean it immediately stops working. It can soldier on for many years, like my unsupported HL-2270DW. But eventually, it won't be able to keep with all the changes to Windows. And when that happens you'll have to be your own tech support, until eventually you need a new printer.