As a BGO, I have a slightly different view. Interview write-ups should IMHO be completed as soon after the interview as reasonably practical while thoughts are fresh. Some BGOs may want to wait before submitting for the reasons stated above but (again, IMO) submission should not be delayed significantly once the candidate has completed 100% of his/her packet.
In my view, there is no excuse for more than a month to go by without submitting the interview. That's just not fair to an anxious candidate who worries that the BGO forgot and is at a loss as to how to proceed. Yes, BGOs are busy people but we also agreed to do this volunteer job and thus there is an expectation on the part of candidates and USNA that we do it competently. So it annoys me to read the above.
It is true that USNA does put pressure on BGOs to complete interviews once the candidate's package is otherwise complete and, eventually, the package will be reviewed without the interview. But that really shouldn't happen absent a totally unforeseen event and, even then, the BGO can notify the Area Coordinator who can sort everything out, including updating the candidate as appropriate.
At this point, I agree it doesn't hurt to wait for another week to contact the BGO but it's a sad state of affairs.