Although this works and doesn't (normally) cause problems, the safety is there for a reason. Once you guys get it figured out the simple way (and if you still have spare time, a rare commodity) I would recommend figuring out a way to update the motors regularly.
AutonomousPeriodic, like the name suggests, runs periodically, just like teleop periodic. The programming "structure" (it's something you have to create on your own, not a built in java thing) that allows you to do this is called a state machine.
But once again, this is just for if you have time, and if you want something to try during offseason to help you next year. I doubt that it will cause problems for you now.
