You don't have to make a decision today...but you did make plans to watch the fight w/friends. At some point, once you know what he's doing, you can decide.
I'm going to share w/you what I would do, but that doesn't mean you should do it....I would continue on w/my plans as they are already set up.
What he may or may not do at this time is on him and you certainly can't rely on him to get the time off or have things ready to go. He may very well be planning on you taking care of everything for him...now, that would be a hoot because you just might have leave it all to him to do. Mom, if your man/child manages to pull this off, I think you owe it to yourself to have a night out w/your friends and leave him to his. Just my two cents.
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.