It would seem that the toungue never got fully formed, or it is some type of birth defect. How long does the tongue stay out for? A few seconds? Or much longer? I wouldn't think it would be a huge problem. It's possible the snake could have slightly reduced senses due to an underdeveloped tongue. I would see how the first feeding goes and keep an eye on it. Examine closely for any other possible defects or odd behaviors. Was the BP a normal or morph?

It's really hard to tell if the snake is "happy" or not. Swimming could just as easily be a sign of stress or health problems. We tend to anthropomorphize snake behaviors and feelings to give us peace of mind. I've done it myself. The snake could very well be happy, but could just as likely be unhappy. Just a thought