Originally Posted by Widgets

Many crews are vicious about upgrading nonrevs they know are FAs. Even to the extreme of skipping over non-FA nonrevs. Onboard crew upgrades are shady af.

Edit: If I were on the revenue upgrade list and saw a Delta employee (careful to know it's a Delta employee) upgraded, I would definitely talk to a flight attendant and ask why it's okay to skip all the revenue customers? I'd be to say verify the working FA's name a couple times to subtly suggest I might follow-up. All being polite, of course.