Going on record with this makes me wonder whether Japan hasn't communicated by back channels a threat to rescind Article 9, and possibly even declare itself as a nuclear weapons state, if they don't let the resolution pass. (The comment from the Defense Minster a while back about a decision for nuclear weapons on Monday sufficing for acquisition by Friday suggests that such a threat would not be vacuous.)
Yes, it is entirely possible. The last thing China wants is nuclear Japan unshackled from Article 9.