[nailer]

Does that mean windows could make any file system case insensitive?

[ElectricalUnion]

Any OS can "make a filesystem case insensitive"; for example in Linux you can do it if your kernel has support for it[1].

But again, that is a OS implementation detail thing, the underlying file system is still case preserving.

[1] https://www.collabora.com/news-and-blog/blog/2020/08/27/usin...