No, NTFS has always been at least optionally case sensitive; current Windows versions even allow case-sensitivity to be controlled on a per-directory basis[1], which even works for (some) Win32 programs:

  Microsoft Windows [Version 10.0.22631.3593]
  (c) Microsoft Corporation. All rights reserved.
  
  C:\Users\jtm>mkdir foo
  
  C:\Users\jtm>fsutil file setCaseSensitiveInfo foo
  Case sensitive attribute on directory C:\Users\jtm\foo is enabled.
  
  C:\Users\jtm>echo bar > foo\bar.txt
  
  C:\Users\jtm>echo Bar > foo\Bar.txt
  
  C:\Users\jtm>dir foo
   Volume in drive C is Aristotle-Win
   Volume Serial Number is E4AE-428B
  
   Directory of C:\Users\jtm\foo
  
  2024-05-31  17:55    <DIR>          .
  2024-05-31  17:55    <DIR>          ..
  2024-05-31  17:55                 6 Bar.txt
  2024-05-31  17:55                 6 bar.txt
                 2 File(s)             12 bytes
                 2 Dir(s)  41,524,133,888 bytes free
  
  C:\Users\jtm>type foo\bar.txt
  bar
  
  C:\Users\jtm>type foo\Bar.txt
  Bar

[1] https://learn.microsoft.com/en-us/windows/wsl/case-sensitivi...