Progress

Yes, the answer really does make sense - if you know the context!

The Meal

  When Dad is out in the evening, we're a bit more relaxed about what dinner is.
  The boys & i like this casserole called Turketti that Dad doesn't care for.  It's a basic meat/pasta/can soup/make it what you will deal, but it wants a few hours to marinate.
  Since i didn't get to it in time, i asked Max if he wanted it for lunch tomorrow or dinner tonight.

The Conversation

  i should say, i wrote the choices.
  He checked, "Lunch tomorrow."
  Later i was going over the schedule for the rest of the day with him.  He was agitated & indicated turketti for dinner tonight. 
  The above illustration shows our conversation at that point.

Why It Makes Sense

  Yeah, it sounds off the wall.  But tomorrow is the day Max and Boom take the hot water washables to the laundramat.  We call it lunch and laundry.
  Lunch out.  NOT the time for a special lunch at home.

Why It's a Breakthrough

  Max has trouble with word finding.  He has trouble with "why" questions. 
  Here he is, out of the blue,  coming up with not only a word but a reason WHY. 
  This is a really big deal.
  Not sure he gets the "why" part of it, but it's something we can build on.