I understand your question. The way this works is that post-interview, you receive a priority score. 1 is best, 5 is worst. If you're higher than 3.5, you're rejected. If you're less than 3.5, you're put on hold till the next offer date. For that offer date, they accept a specific number of people (about 50), and they set the threshold so that all people below a certain priority score are accepted.
So, let's say your priority score is 2.2. For the October 16th offer date, in order to accept 50 people, they find that the priority score threshold must be 1.9. You then remain on hold. For the Dec. 15th date, they must perform the same process. Remember that more will have interviewed between 10/16 and 12/15, and some of those interviewees will have received very strong scores, such as 1.2, and others will have received worse scores. So, it's possible, depending on the strength of interviewees, that the priority score threshold could actually drop for the next batch, say to 1.6. If the group of interviewers wasn't as strong, the threshold may be set at 2.2. In the latter case, you'd get in on the Dec. 15th date.
The bottom line is that it's impossible to predict what the priority score threshold will be and even if you could, since you don't know your priority score, you don't know where that leaves you. Your best bet is probably getting in at the first available offer date after you've been reviewed, but it's still possible that you'd get in at later dates.
Let me know if that cleared things up or only muddied the water further.