All martial arts on some level is for self defense, we are talking about sport. You think the top BJJ guys now don't know self defense? Most of that stuff is white belt basic shit
I think about 20% of sport BJJ techniques won't work in MMA, but that can be said about every art including Boxing, Muay Thai, Wrestling, etc.
Wait till some of these modern BJJ guys like Garry Tonon, and Neiman Gracie continue going in MMA, they're proving the new innovations in leg locks absolutely work in MMA
Ironically Neiman Gracie just finished JON FITCH with a Heel Hook