No one just "goes to the ship" unless general boarding has opened. Prior to that, everyone is in a holding area, albeit Suites & Elites have their place versus Platinum. Not sure where Reserve Minis go, but used to be group with Platinum. Once general boarding begins, they let the priority groups on first, followed by the rest. "The rest" are not held back for arrival of other Elites/Platinums.
Once general boarding is underway and the terminal waiting areas are cleared, newly arriving guests just head onto the ship after clearing check-in, regardless of CC Member level and cabin type.