The Junk Drone was officially moved back to A20 as they are rethinking parts of it to make it more modular. Which needs a lot more work to improve the current mod system to allow it and also vehicle mods.
Basically as a result the default Junk Drone will be nothing more than a cargo mule to bare your burdens. While allowing you to upgrade it with various mods to add more features to it. Such as being able to attack zombies or heal you to more cargo space and so forth to fit your needs.
In other words instead of just being a flying turret companion it is getting more fleshed out to be even cooler then before.