I don't think they gonna buff one or nerf the others, but I hope they introduce abilities and items you can use during fights.
Also they must change CP placement in gyms now, there is no hope for this game at least for legal players if CP is still what matters after the rework. If they make it so you can only place one mon of each kind no way I am gonna prestige 10k to put a Slowking for example if he is gonna be out the first.
On the other side if I am the first to arrive (almost imposible with cheaters but imagine so), and put my Dragonite for example, they will have no problem to take down the hole gym even if it is level 5-6-7 just to prestige it again and put their own Dragonite.
So Niantic has to think really closely about this, gym placement and restrictions are related, one thing influences the other directly.
