What was the point in his text message to me?

You did the right thing. He is definitely on the rebound. If you start sleeping with or dating him its gonna be really good for awhile then suddenly he's gonna dump you when he stops missing his ex. This is how rebound relationships work. He texted you because he's lonely and looking for someone to fill the void his ex has left. He may miss his ex or if not her specifically he just misses having someone around. You are smart to not want to get involved. Guys on the rebound are very dangerous to get involved with, unless you don't mind just a temporary relationship.