I have been worried about this mythical two week rule.
My committee letter isn't in yet. I am sitting on 2 secondaries that are 2+ weeks old and two that will hit 2 weeks old on Friday. I assume I am ok since it isn't like my application would be complete with my secondaries right now.
However, the second my committee letter gets in, you can bet your bottom dollar that those 4 secondaries will be in so fast.