What happens to my ds status if he doesn't receive a scholarship 3rd round? Does his status change from boarded?
His status will remain as it is now if he does not receive a scholarship offer. Around the first of may he would most likely receive an official notice that he had not received a scholarship. There may be a few scholarships given out between now and then depending on what is left over after the final WP appointments and any applicants that decline their offer.
If your son does not see a status change soon make sure he keeps in contact with the ROO at the school he decides to attend, keep his name out front so to speak. Some battalions have offered scholarships before the school year starts, many will wait until the new class of cadets start the program and then evaluate each cadet for a possible scholarship offer if they have any available to give.
If this board follows the same process as the last board, all the notifications were posted at one time and the letters were sent out along with the online notifications.
Your son will need to keep pushing forward, be ready to do well on the first APFT, start school strong and have a good first semester GPA, be fully involved with ROTC, do well at all these and he will keep himself in a position to receive a battalion scholarship if they have them to offer.
Best of luck to your son, I hope he hears good news.