I remember a few years ago that Microsoft docs started to point to Mozilla docs, maybe part of Edge rebrand? Perhaps renaming to MDN during this agreement could leave someone like "huh is it M(ozilla)DN or M(icrosoft)DN??". I have no clue.
For the curious, MSDN is now called Microsoft Docs.
To the surprise of many, much of the documentation on the site is also open-source[1].
[0]: https://en.wikipedia.org/wiki/Microsoft_Developer_Network [1]: https://github.com/MicrosoftDocs
See also Apple, who, after a relatively brief dalliance with the name iTools, rebranded its online service as ".mac".
Sigh...
I miss early Internet names like these, although I suppose the fact that the original dot com era didn't last and a bunch of early startups got wiped out - Pets.com, anyone? - gave it a stench that marketers were all too willing to run away from at the first possible opportunity.