That would make sense and super sneaky for UFC to pull to get a deal done, but did he walk out before or after they announced the date? If he walked out as soon as the promo started, it could have been the main event for MSG. If he walked out as soon as he seen the date and venue, then that would be telling.
Edit to add: Found a video in another thread (
http://forums.sherdog.com/threads/nate-diaz-leaving-the-press-conference-early-video.3806753/)
Nate Diaz leaves as soon as the video starts before the date is even announced. He got salty just at the Khabib vs McGregor fight, not at what card it was booked on.