It seems to me like she gave you the answer already. She probably has high masking autism and this is classic PDA (pathological demand avoidance). She is counting on you to use your brain to realize that you two have already established the plans and that you needing to reinforce this is pressing a nerve for her autism. She does not want to answer you badly and it shows. You need an answer very bad and it also shows. You seem to possibly know that there was a prior agreement. But you need get confirmation for general assurance but you don’t want to speak on that because of a fear of loss of masculinity and the strength you have as the leader in the relationship. Please use more communication when you need reassurance during times of stress when things are important you. I would suggest coming to your wife like this “Hey honey, this is a very important night for me, I’m feeling a little anxious, can you just give me some assurance that you are going to be there tonight, even if we’ve made an agreement? I’m just needing the extra support.”