I am pretty sure Kobo is using bog-standard `mkfs.vfat` to create the drive, I don't see what is so obscure about that.
Perhaps something about the way it is exported?
Regardless, the fact that every operating system for years and years and years has never had a problem, up until this one version of one operating system, implies that it is indeed Microsoft's fault.
And I very much doubt it is necessary for whatever reason they may have had to modify the USBMS driver.
...
Yes, ideally Microsoft will fix this rather stupid bug.
But I guess Kobo cannot rely on that.
I do wonder how Kobo can possibly fix it properly, given that their devices keep a factory restore firmware which will still contain the code which triggers Microsoft's bug.