What is the (if there is one) deadline for team registration for the 2016-2017 year?
There is none.
The real deadline you want to watch out for is when the events in your area fill up. Don;t be locked out. You have to be registered as a team prior to signing up for an event so sign up earlier than later.
Schools just want to get through the current year and we are still setting dates for the new season so not all the events may even be planned for your area at this time.