[bigpicture]

Not being familiar with the term XNU, I did a little clicking around and hopefully I understand a bit better:

This file is evidence that Apple has been running iOS/MacOS on the Raspberry Pi 3?

[Wowfunhappy]

It's evidence they have been running the macOS / iOS kernel, yes.

Whether they had the full stack running—and how much of the stack is necessary for something to be deemed "macOS"—is up for debate.

[lukeh]

Or maybe it was an intern project.

[bpye]

Heh, this is quite believable too. Anyone found their LinkedIn profile?