This trait of love is longer, because it has two parts. The parts are a comparison of a negative and a positive. “Love does not rejoice with unrighteousness, but rejoices with the truth.” Or, in other words: “Love is not happy when bad stuff happens; love is happy when good stuff happens.”
The comparison is between unrighteousness and truth. God designed and created the world. He designed the way it should work. That is the truth. If the way things work agrees with the truth, that is good. If the way things work do not agrees with the truth, that is bad.
Righteousness is a word that refers to a person’s relationship with god. Before we chose allegiance to God, we made the de facto choice of allegiance with sin and the world. We are living in a state of unrighteousness.
When we choose allegiance to Jesus, the grace of Christ negates the penalty of sin, adopts us into the family of God, and declares us righteous. We have moved a long way back toward how we were designed to live. We agree with God. We agree with the truth.
God’s heart is that everyone would move here. God’s heart is that the universe would operate according to his design. Earthquakes, genocide, sex trafficking, environmental destruction, bullying, and left\right political bickering are not part of his design. They are not part of the truth. God did not create them. God did not orchestrate them. God is not happy when they happen … except for the hopeful possibility that someone sees these things, wakes up, and seeks him, embraces the truth, and chooses allegiance with God. God will rejoice in that aspect of it. God does not, and will not, rejoice in the misery and pain these things cause.