According to the Catholic Tradition, Are People in Heaven Waiting for Other People to Die? According to the Catholic Tradition, are people in Heaven waiting for other people to die?
Or are they very busy chatting with God, the angels, and other people who have already died and gone to Heaven?
Since Scripture is part of Sacred Tradition, yes, people who have gone to heaven are waiting for the rest of the body of Christ to be filled up:

Revelation 6:9-10 And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held. 10 And they cried with a loud voice, saying: How long, O Lord, holy and true, dost thou not judge and revenge our blood on them that dwell on the earth?  11 And white robes were given to every one of them one; and it was said to them, that they should rest for a little time, till their fellow servants, and their brethren, who are to be slain, even as they, should be filled up.