Once the other commissioning sources (SA/ROTC) request the exam, the results will be given to them. DoDMERB's job is the medical clearinghouse, for simple terms. Their job is to perform the exam, Q or DQ. The commissioning sources will decide if a waiver will be approved. Every SA and ROTC HSSP will be able to use the same exam as their medical requirement.
They will determine when they want the exam results from a move forward perspective as a candidate.
Use ROTC as an example, ROTC candidates are not offered the exam until they are awarded a scholarship. That is their process. When your DS gets a scholarship they will than use this exam. There will not be another exam. However, at the same point, it has no impact on his chances for getting a scholarship.
Do not read anything into getting an exam early or which source requested it. Just wait for the results, and if a remedial or DQ comes down, get in front of it, because it can takes weeks or months to get a waiver.