Because it's the only website that talk about the OTHER registry key to remove OneDrive from the CURRENT_USER navigation panel, not just the explorer.

For reference:
The .reg files below will modify the DWORD in the registry key below.

HKEY_CURRENT_USER\SOFTWARE\Classes\CLSID{018D5C66-4533-4307-9B53-224DE2ED1FE6}

System.IsPinnedToNameSpaceTree DWORD

1 = add
0 = remove

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace{018D5C66-4533-4307-9B53-224DE2ED1FE6}

(add) = add
(delete) = remove

The second is the good one.