What does he want? Is he just trying to be friends?

I sent this guy a message congratulating him on graduating because I didn't want to be a jerk even though things got messy between us. Well, I was not expecting him to respond but he did yesterday which was two days after I sent him that message. He thanked me for congratulating him and then wished me a happy Independence Day. Is he trying to be friendly or do you think he wants something else?