I also appreciate that they did not attempt to tackle filesystem encoding here, which is a separate issue that drives me nuts, but separately.
Windows badly dropped the ball here by not providing a simple opt-in way to make all the Ansi functions (TextOutA, etc) use the UTF-8 code page, until many many years later with the manifest file. This should have been a feature introduced in NT4 or Windows 98, not something that's put off until midway through Windows 10's development cycle.
Recently, i've gotten bit by UTF16 (because somewhere along the line somewhere on a windows machine generated a file by piping it in powershell)