No Priority Passengers
It’s true that boats separated people by economic class. However, to be more specific, they separated people based on what ticket they held. That’s why it would’ve been impossible for Jack to climb to the upper floors and meet Rose, making the entire plot of Titanic one huge mess.
However, when it came to the safety of the passengers, no one had priority. The scene where the ship’s crew locked the gates to stop the poorer passengers from fleeing to safety was bogus. In fact, in the real-word event, the captain ordered the crew to unlock the gates. Everyone was ushered to safety.