Okay, that might be the case.
IMO, if its not the refugees, its likely to be the backlog. Many people are saying that the backlog is too huge to be cleared by September. Half of the immigrant quota this year is supposed to be non-EE applicants from the backlog. It makes sense that they might have a quota for the number of applications in backlog to be cleared this year.
There wasn't always a bottleneck at 481. It happened because they reduced the number of EE ITAs because of a reason we can't be sure of yet.
We will find out by September hopefully if this really is the case though.