Right now, we have 2 pilots and 3 different crew models, and a bit more than 200 different airline operators. If we wanted to do multi-liveries for them using the current system, it would require 1000 ( 3 + 2 * 200 ) new Simobject variations JUST for the pilots+crew, and this would affect the sim startup time, the memory used, the speed of the airplane selection page, and the startup time of a multiplayer session and the P3D scenario editor.
With the new DirectX-based way of making company logos that we'll introduce with the next update (that's why it's taking so long: it will change *everything* in the way the objects are organized), this might be more feasible, since we would still have only 5 models, possibly with some color variations for the uniforms, but they would still be 10-12 models at most, since the DirectX rendering will take care of drawing the airline logo.
We'll use this system entirely in the next GSX update for the ground handlers, the catering vehicles and the jetways. We might extend it to the crew as well, not sure if in the initial update, but it can be done.
Of course, with P3D 4.4 minimum, since FSX doesn't have the crucial feature (Render To Texture) in its SDK so, FSX and older P3D version users will still have to deal with the old system (time to upgrade...)