Double post, I know, but in case anyone posts as I'm writing this...

I need to go right now. I'll be back later, but a lot could happen between than and now. I can't make you, but try not to do too much while I'm gone? Maybe? Please?

Also, we could say that the time between Aria arriving and Super Boy arriving being just seconds within each other. Aria arrives and BOOM! There's Super Boy! Everyone is more or less caught by surprise. Because Dark Matter thought and told Jack that the Teen Titan's were too bogged down to make up any plans or actions, so even he won't expect them.