As long as we're keeping it real...the SEC doesn't give a rats azz if they are buddies or the worst kind of enemies...and the PCAOB doesn't care either. Bottom line is a letter is expected, and it needs to be there within a reasonable amount of time. Along with that, the SEC doesn't go ask...they expect the company to be PROFESSIONAL....make that both companies.... and respond within a reasonable amount of time by requesting...and receiving what is required.
I don't believe...and just my personal opinion...that the previous auditor would be holding back from such a request. They have nothing to gain or lose in this by doing so....unless..."something" in a previous filing they audited was not quite as squeeky clean as it should be...and was allowed to slide on by?