right now the story is on age gap between JB and meera does not look of jai's age either. she looks of bani's age so how can jai once again marry the girl of half od his age and gets same humiliated dialogues regarding his and his wife's age gap once again?
if JB seperation happens, that would be only because jai thinks that bani left him because he is too old for her and one thing would be settled in his mind "not to marry the girl half of ur age ever again" so i dnt think he would repeat the same mistake again marrying meera.
i think meera's charactor is there to teach a lesson to both jai and bani. bani would be jealouse of meera and would realise that she needs to give more time to her house, her kids and most importantly her husband than any jasoosi. and jai would be helping meera to get back to normal life (as bani helped daksh) but others would think differently and only then jai can realise that may be bani was doing the same and he misunderstood her.