First off, for one, I fully agree with everyone here who is blasting the OP. They had the set defense tool out there for a week, with a big annoying red dot on the Arena node that even required you to set 3v3 defenses (Absolutely CANNOT wait to have my Omicrons on Starkiller not able to do anything!). So, someone complaining about auto-deploy not happening is just *chef's kiss*.
One thing I would suggest is to require the defense table to have been set before allowing sign up for the event. Don't have anything set on defense? Can't join. Put something in the table, even just a single team? Cool, enable that green button.
I'm also LOL'ing at the "I don't have time to set the defense" but has time to post repeatedly on the Internet forum about it dichotomy going on here.