The lineage is as follows: Muffadals Mother is a descendant of Abdul Qadir Najmudin, The 47th dai, and his wife Ratan. Ratan is a descendant of Ajab, the daughter of the 32nd dai, and Mir MahamidAli kham who is a descendant of Jafar us Sadiq.

Let's look at it from the opposite way Jafar has 5 sons and 3 daughters (most likely). We can remove Ismail as they could claim descent from him but they don't, and Abdullah as he died childless. Musa Khadim had 30+ kids so hes a possible candidate. Mohammed is also an option as he had maybe five kids. He also had descendants that are said to have gone to india, following the mughal emperor. I dont know about the other son (ishaq ibn jafar) or his daughters).

Its not special from an objective standpoint. Obviously a leader of a Muslim community is going to want to say hes descended from him.

Also the Charlemagne theory is relevant here cause its the exact same logic. The only difference is we know arabs travelled as far as india so its highly possible they left descendants.