As the title said, the Auric Missions and quickplay do not force anyone to be level 30 in the lobby except for selecting them.
You, as a level 30, can still end up in an lobby with people below level 30. This isnt due to striketeam having a lowlevel and queuing for those, I was the only level 30 in the lobby.
I expected that you can only queue with other people on level 30 if you do Auric Quickplay.