|No such thing as a small change|
Hm. I'm not sure that the term "re-write" comes into it anywhere.
Windows NT was a completely new OS written from scratch.
Bits (Kernel API; UI; etc.) of that new 32-bit OS were backported to the newer versions of the old 16-bit versions of Windows in order to provide a migration path.
Saying one is a re-write of the other is like saying OSX is a re-write of MacOS. They are both essential very thin skins of look&feel layered over completely different underpinnings, design philosophy and target audience.
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.