Is it sure it will be in France?
Anyway Laurent never does the same as anyone else...
I don't really think people would mind very much, Louise is only 11th in the line of succession. Her parents have a more private life than the king and queen, or Filip and Mathilde. And a baptism is regarded as a private ceremony in Belgium, not a public one.
But I do hope, if it really is in France, that there will be photos and some footage!