When I set a repeatable parent task (e.g., Jon Smith’s annual review), the moment I mark that task complete, the subtasks attached to it are added back to my Asana task list, even though they were marked complete before. It seems that when the parent task is copied for the repeatable time frame set (annually in the example provided), it copies all subtasks with previous due dates and assignees. Is there a way to prevent this from happening and have only the necessary information roll over when a task is set with a repeatable due date?
Hi @Matthew_Rosario , welcome to the forum 
Unfortunately, for better or for worse, this is the expected behaviour. There are workflows that benefit from the subtasks being recreated in the next recurring parent task but I agree that due dates on subtasks don’t really work in that case.
You could experiment with task templates instead, where subtasks could be X days after creation date. You could create a rule that will create subtasks instead, however, you will find that rules will not trigger on recurring tasks unless you use a manual trigger, for example. 
Is Asana considering building functionality to allow repeatable/recurring parent tasks to toggle subtask duplication on/off? Additionally, if the subtasks are also repeatable, would it be possible to build a function to reset due dates when copying the parent task? This “expected behavior” is a significant nuisance in our day-to-day operations, where many of our processes are repeatable. Completing one task generates multiple old tasks that clutter task lists.
I don’t know @Matthew_Rosario , I don’t work for Asana - I’m a volunteer forum leader.
I appreciate it can be annoying, like I said, especially when due dates ‘lag’ behind. But for some workflows, it is actually useful to have all subtasks added to the next recurrence.
It might be best to search the forum for existing threads in the English Forum > Product Feedback category, otherwise create a new request of what you described above. You would have my vote 