mom3boys, did your initial letter state that the file was complete (this info should be promulgated on the website), or did it state that he is scholastically qualified? This might be what is confusing midlax.
The majority of what is coming out of the admissions people right now are the LOAs and athletic offers. Remember the vast majority and that their package completion deadline is not until March. An appointment decision cannot usually be made until all the MOCs slate's applications are completed.
Therefore, for USNA, at least, and probably for the other SAs, there is no great sense of urgency to get the files before the board and qualified. Where future inputs such as new ECs, mid year grades, and improved SATs could weigh heavily in the acceptance decision, these records are either not placed before the board or may be deferred until as late as Feb or March.
My supposition is that WP does not send a letter when the file is complete but only when one passes milestones in the selection process, the primary being scholastically qualified.
There is a reason for the agonizing slow wait. For most, however, no news is good news.