If you don't use Bishop that's fine, but there are people who do dungeons either regularly or through the leveling experience, so tossing them a bone is at least good. I want to consider all forms of content, not just boss fights. This would also be quite big in things like Eureka and Bozja where there are definitely needs to have AOE's very regularly. That and the rare occasion where you do have to deal with more than one enemy in a boss battle.
Again, I mostly just want Bishop to return and Machinist has so few buttons that it wouldn't do any harm, but if Automaton Queen did AOE damage each hit, I wouldn't mind although I do miss my turret since Stormblood. It does make me curious what you would bring back or add though in place of the Bishop at any rate. I've had a few thoughts with revamped Heartbreak Shot, Stun Gun, and Lead Shot, although as a replacement for Bishop, it wouldn't be bad to have a button that wasn't required to be hit all that often which Bishop at least fills along with Automaton Queen.