The subject has been poked at a few times, from curiosity surrounding the ruins in duel and the desert map (name escapes me) and boss battles have been mentioned and spoke on a bit during the adventure mode kickstarter. I also remember reading a little bit somewhere pertaining to the massive ships in regards to "If only we could find out who keeps making these things..." insinuating there are more than just ruins of these leviathans about the world.
So from the insinuations of them still being produced, boss battles and the simple fact that they HAVE existed, one might imagine we see these pre-war re-fitted warships with balloons to carry them.
But assuming a great many things, what role could they possibly serve in the overall game world? Could any particular nation lay claim to them? Or does one in specific have agency? Would they be more of a "random event" kind of deal, or even a balancing one in which a faction pushed too close to the brink lashes out desperately with technology that should have been left buried?
Assuming they exist, what role might they serve?