Can I assume that you saw this on his calendar? If so, I wouldn't say one word to him about it at this time. Why do I say this? Since he knows that you can see his calendar, he may have just put that out there to get you to break your NC w/him. If this is an actual appointment, allow him to come to you and tell you that he's met w/an attorney. It's time that you allow him to take a lead in this particular dance. You've done all of the work and worrying, give the man a chance to contact you about this one particular item. In the meantime, I would still get my ducks in a row and be ready for when he does contact you.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.