I think this is ironic because no one wants Francis. His parents like to get rid of him for Christmas so they can go do what they want to without a kid. Scout makes it sound like Alexandra has to take care of him, not that she looks forward to it.
Scout and Jem, likewise, would prefer for him to be absent. He is a nusiance.
I am not sure if Francis understands that he is not wanted, so even though hypocritical would be an accurate assessment, it might be closer to irony. To be a hypocrite, you have to know what you are acting against.