Another thing they could do with the exisiting commanders would be, for example, to break down all the commanders any player posesses into their component abilities, or even into Supply, and let us build whatever we want from the parts.
This way, a player that got, say, the Elite Troops Doctrine before, would now be able to include its unique abilties (Tiger Ace, Troop Training, Stun Grenade) into custom commanders, whereas someone that didn't would have to hope for a lucky drop from a package bought with Supply or such.
That was what I was thinking of as well when I read the news. Finally duplicate commanders would make sense.