Bruce and Alfred had a conversation about it earlier in the movie. Alfred talked about how after Bruce went missing, he would go on vacation to France and go to the same cafe and wish that he would see Bruce, and they wouldn't talk, but Alfred would know that Bruce was alive and happy, and blah blah blah. This is why you gotta listen to all the dialogue, not just the action-y bits, or you miss the callbacks to earlier scenes. It wasn't a great ending, but it was better than, for example, the average ending of a Stephen King book. God I hate his endings sometimes.