It's a style of humour unto itself. The lack of humour is itself humorous. The real question is whether or not he thinks he is being directly humorous or ironic

It's a style of humour unto itself. The lack of humour is itself humorous. The real question is whether or not he thinks he is being directly humorous or ironically humorous. I wouldn't be surprised if it was the former. Plus he's rich so people probably laugh at his jokes regardless.