That's an interesting suggestion! I'd be really happy if that were the case, honestly, because I love French - but there are three reasons I think it's not.
1) I've never seen the French chouchou used in English before, and I'm Quebecoise. We have at least one of, if not the healthiest and most deeply involved mixes of French and English in the world here.
2) Not to sound like an ingrate - I know how many hours of work go into scanlation, and have first hand experience with Japanese to English translation specifically; and it's hard. I admire anyone willing to take on that challenge and then release their results to a world that isn't very afraid to criticize, and definitely appreciate being able to read this manga in English. That said, to put it somewhat bluntly: the translation is not very good. Unfortunately, passion and hard work alone do not guarantee good results, and the available release of this is frankly quite lacking in the translation department. It's rife with errors, so I wouldn't be surprised for the title to be one more.
3) Even if it is meant to be wordplay, it would likely fly right over the average reader's head, because in context it just looks like the Japanese word for butterfly. Even people who don't know what "chouchou" means in Japanese are likely to follow normal conventions and read "ou" as an extended "o", even though "ou" isn't supposed to make that sound in English.