i don't have even a slight doubt on them participating in NB and i don't even want them to. That show has lost its credibility in its last season for me! Moreover, parica do not have enough time for their health, so participating in that show will be very very tough for them and it will give away their relationship (if they are in it or not) on the face. Though they might come for opening episode or one performance but participating altogether? No no no!
Same I too feel they will only come in opening episode give a performance as AnuPre. Just cashing on their popularity for the buzz