The fact is that there are two offices, one Messiahhood and the other Mahdaviyat, and out of the two, one with much wider, worldwide publication is that of Messiah, not of Mahdi, because Mahdaviyat is known only to the Muslims, while Messiahhood is worldwide known not only to the Christians, but also to the Muslims and the Jews.
So the three most important nations of the world, which if joined hands together will conquer the entire world forever, rule the entire world forever, are Jews, Muslims and Christians in their own respective way, they are the strongest people on earth. Not if they are warring with each other, but when their might is put together, I mean. So all these three nations believe that Messiah would come, and also they believe that the golden age, that myopic age, which has ever been eluding man, would appear after the advent of Messiah.
So because this is the most commonly known phenomena, the coming of Messiah, this is why automatically the Ahmadi literature shifted to the use of Messiahhood. And also because the Ahmadi knew themselves that there are not two persons. The person is one, and he would be holding two offices. So practically it doesn’t make any difference. Mahdaviyat is understood by Messiah, and also you must have heard, and the Ahmadis present this by way of argument to non-Ahmadis, that Anh-Huzoor sallallahu alaihi wa sallam is known to have said, lal mahdiyo illa eesa, Mahdi and Eesa are one and the same thing, there won’t be any other Mahdi than Eesa, or any Eesa other than a Mahdi.
So all these things make that preference of Messiahhood very insignificant, doesn’t make any difference if you don’t mention the name of Mahdi, it is a part of Messiahhood, it’s not different.