I got an answer from the Army - "It is most likely that your son will be coming home on ####, something, something, yara yara. . ." I have no clue what all the exceptions and disclaimers were.
But, That was the best answer I was going to get, so I have just spent lots of money I can't get back - and I'll have to hope and pray that he arrives, while we are there if not, I have just spent 2 months salary on a 3 day vacation to Nashville.
Finger crossed - I hope the rest of the answer's that come to me in life aren't as vague.