Well however it ends, we gotta wait three more weeks for it to finish. It's gonna be worse than watching "Hibike! Euphonium." Though I wonder how an open ending would look, obviously Samaritan will be defeated, but beyond that I can't really think of anything. If it ends like I said, I do know what I would want the second series to be about if it ever got made (Though I'd be just as happy to leave it as is), or it'd be an awesome idea for a fanfic.
They do a timeskip, cyborg technology is safe for use but maybe not widespread. The Machine notices a new threat, cyborg related or not, and creates bodies for the team, downloads a perfect simulation/copy with all their memories into them and have them save the world again.
I will be very surprised if it does happen though.