If you want to know if the guy’s interested in hanging out on NYE, just ask him already. Don’t waste your time and energy being passive-aggressive. Most guys — especially ones who are, for all intents and purposes, in a relationship and therefore not thinking about whether they’re going to find someone to sex them up on NYE — don’t really put much thought into the occasion. It’s very possible that your dude, who lets you initiate everything, simply assumed the two of you are going to do something together and you’ll just do the organizing like always and let him know what’s up.
But perhaps you’re writing because you’ve had suspicions your dude is over it. Or maybe since he is seemingly the kind of guy who never plans or organizes anything, just once, you’d love it if he took the initiative and planned a nice night out for you two. And if you’re feeling either of these scenarios, you’re still being passive-aggressive by setting up this “trap” for him and watching and waiting for him to walk right into it.
If you really want to get to the bottom of his behavior, just communicate with him already. Tell him what you’re feeling. Tell him you want to spend NYE with him and you’d love if he planned something, or at least initiated a conversation with you about plans. Tell him that going forward, you would love if he’d take a little more agency for planning things for you two to do together – that it would make you feel loved and cared for an important to him. This will be far more productive than sitting around waiting for him to either pass or fail a test you’ve set up for him and finding yourself with no plans and a broken heart on NYE.