GW actually threatened to do something similar to this years ago with their last edition of blood bowl. If they saw someone making models that looked like they could be used in their game, they were going to remove star players.
I think really
GW is trying to move more and more to smaller inventory to keep track of, and just give us less and less options until we reach the monotone levels of warmahordes in the sense of not being able to equip your leader how you want and just what comes in the clam shell.
Maybe we'll get lucky and it will have two different pistols, like the admech dominus!