I don't know if they'll go all the way until the 19th, but I do in the past that they have accepted/rejected people all the way up until the last week. So, while they may not go all the way until the 19th, they'll likely go all the way until that week. I can imagine that it might get tricky at the end having to place people because they have to be selective based on what spots & roles are still available.
How long is "quite a while"? I know someone that was just accepted 2 or 3 days ago. They're also currently sending out character performer acceptances in small waves (my friends was accepted as a character performer yesterday). Judging by the constant wave of new people joining the facebook groups, it seems as if they're sending out acceptances every day. But I could be wrong.