Imagine, if you will, a game where the developers introduced a few questionable products in earlier releases, due to a long development cycle and playtesting problems. These products have warped the gamestate into an escalation of arms. The problems then multiplied when future releases with their delayed reaction time and the game has reached a state of growing frustration from many players, especially players of one faction, which was seemingly dealt the worst hand in recent FAQ-s.
Then new releases come and the problem parts of the game same to be expanded upon, with new directions and capabilities, while the weakest faction gets lackluster releases. Nothing powerful or meta warping, just the usual stuff. Decent. None of them becomes the automatic best choice in the game as soon as they hit the shelves.
Now imagine that the developers of this game actually know about the problems, but due to many reasons, their hands are tied about the time of release for many of these solutions.
Now imagine the reason behind one faction getting healthy mechanics that work well with the faction without warping the meta, is the same reason the other factions are getting products with a similar role and function as the problematic ones.
Imagine that there is a plan to this all, and that the developers are not in complete control of their release schedule...
Why are the rebels getting access to two new bombers? Maybe because the problems are about to be dialed down. Maybe there are things in the way that will change the gamestate into a healthier one, and that's why imperials aren't broken.