If the person who appears in the trailer line doesn't match either Maintainer or one of the Uploaders (and if you don't have a line about “Team upload” and some variations in the changelog), you would get this warning.
Cyril explain it way better than me, thanks :D -- Aloïs Micard (creekorful) <alois@micard.lu> GPG: DA4A A436 9BFA E299 67CD E85B F733 E871 0859 FCD2