Do you have any idea just how much code is in Windows?

I did a quick search and estimates are in the 50-60 million lines range.

No way in hell are they going to rewrite all that in a few years. Even if they actually wanted to, which they don't because it would be a truly enormous expense (even for Microsoft).

Not to even mention that huge software projects have a well deserved reputation for failing, and the scope of such a rewrite would probably dwarf any previous rewrite of anything, ever, and by a very large margin.

"Rewrite all of Windows in Rust" simply does not even begin to pass the sniff test.