I've said it before, I truly think there is a computer algorithm that is put in place for apps. One that looks for certain words and phrases. If that process 'sees' a lot of those words/phrases, then you get to move on. If it 'sees' a lesser amount, you go into submission, fewer still and you get locked out. Then, the WBI looks for even more of those things. If the computer 'sees' what it's looking for, you move on to the PI. Why do some stay 'in submission' longer than others? Perhaps they had more of what the computer was looking for, so they are put 'on hold' until the computer sees what comes along, down the road. If the program still has needs, it can go to the 'in submission' candidates. If it has what it needs, kids get NLIC'ed.
It also has to depend on exactly what Disney is looking for, at any given time. If they had a ton of current DCP kids ask to extend, then they won't need as many new DCP candidates. There truly doesn't seem to any rhyme or reason to the lay person, that's for sure!