the audie is right in some respects, in my opinion.
southern has been exposed to the deaf community, which holds very strong views on very controversial specific subjects, such as signing and CI's....however, he has NOT(edit: to my knowledge, if you have then please, correct me) been exposed to the flip side of that coin, successful oral deaf, successful CI's who still sign, or the negative aspects of deaf culture. He IS biased....that does not mean he is definitivly wrong however, just that he himself does not have all the facts.
i dont mean to sound elitist here, but i've been exposed to the flip side, ive seen successful oral deaf who do not want to sign, and they function fine as productive adults.ive seen many CI users who sign and while i support learning sign 100%, i also support CI's for people who want them, and i do support implanting children.
learning sign and speaking/hearing are not mutually exclusive, so that is a non-point really. if your boyfriend wants to sign, who cares what the audie tells him, really.
i really fell you should let him research CI's for himself, let HIM decide what is best for himself, and support his decision either way. CI's are successful(notice i didn't say cure), and they are simply another tool for a person to use should they choose to do so. even if no more than environmental sounds, least he will be aware when something around him happens.
Deaf culture is not the be all end all for deaf people. Deaf culture can be very exclusive and downright small minded in their views about people, espically late deafened. I have no doubt at all that your friends will accept him, my friends would do the same. But wether he will become a part of the deaf culture anymore than you or I as hearing, is pretty doubtful. His views on controversial subjects will not be respected, he will hear mean things, he will deal with elitist attitudes of people who will claim he isn't "deaf enough". he will never be a native signer, and it will always be noticeable.