Yemenite Jews have a mesorah. They kept records of marriages, divorces, and conversion. They had valid Batei Din. All the "lost tribe" groups lack this and therefore require full conversion to become Jewish.
So are many of the Jews during the Shoah and Inquisition who were forced to become Catholic and lost touch with their heritage now non-Jews?? If a child is taken from his Jewish parents, like placed in an orphanage and marries another Jewish woman frmo the same orphanage and grow up under a Catholic family, do their children need a conversion, once they find out they are of a Jewish ethnicity or background?
Speaking of which, considering the multi-generation of hedonistic Jews in Galut who also did not grow up with a mesorah, why are they any less obliged to under a conversion as well?? I suppose that may even include myself, since my parents were secular , non-practicing Jews.. Although my father was did have a bar mitzvah, he never taught me anything of Talmud or Mesorah and I had to learn myself later in life. I also grew up around goyim and was influenced by them.
I guess this will become a very complicated subject, but to me, to refer to any group of people who are Jewish, yet cut off from mainstream Judaism, as non-Jews doesn't seem respectful to Am Yisrael who have been cut off and separated over the generations, especially in Galut.
Because much of the Beta Israel's history is passed orally from generation to generation, we may never truly know their origins. Four main theories exist concerning the beginnings of the Beta Israel community:
1) The Beta Israel may be the lost Israelite tribe of Dan.
2) They may be descendants of Menelik I, son of King Solomon and Queen Sheba.
3) They may be descendants of Ethiopian Christians and pagans who converted to Judaism centuries ago.
4) They may be descendants of Jews who fled Israel for Egypt after the destruction of the First Temple in 586 BCE and settled in Ethiopia.
Without regard as to which theory may actually be correct (and each theory has its support), the authenticity of the “Jewishness” of the community became an issue.
As early as the 16th century, Egypt's Chief Rabbi David ben Solomon ibn Avi Zimra (Radbaz) declared that in Halachic (Jewish legal) issues, the Beta Israel were indeed Jews. In 1855, Daniel ben Hamdya, a member of the Beta Israel, was the first Ethiopian Jew to visit Israel, meeting with a council of rabbis in Jerusalem concerning the authenticity of the Beta Israel. By 1864, almost all leading Jewish authorities, most notably Rabbi Azriel Hildsheimer of Eisenstadt, Germany, accepted the Beta Israel as true Jews. In 1908 the chief rabbis of forty-five countries had heeded Rabbi Hildsheimer's call and officially recognized the Beta Israel as fellow Jews.
In reaffirming the Radbaz's position centuries before, Rabbi Ovadia Yossef, Israel's Chief Sephardic Rabbi, stated in 1972, “I have come to the conclusion that Falashas are Jews who must be saved from absorption and assimilation. We are obliged to speed up their immigration to Israel and educate them in the spirit of the holy Torah, making them partners in the building of the Holy Land.”
In 1975, Ashkenazic Chief Rabbi Shlomo Goren wrote to the Beta Israel telling them, “You are our brothers, you are our blood and our flesh. You are true Jews.” Later that same year the Israeli Interministerial Commission officially recognized the Beta Israel as Jews under Israel's Law of Return, a law designed to aid in Jewish immigration to Israel. The Beta Israel were ready to come home.
Indeed, the Beta Israel were strictly observant in pre-Talmudic Jewish traditions. The women went to the mikvah, or ritual bath, just as observant Jewish women do to this day, and they continue to carry out ancient festivals, such as Seged, that have been passed down through the generations of Beta Israel. The Kesim, or religious leaders, are as widely revered and respected as the great rabbis in each community, passing the Jewish customs through storytelling and maintaining the few Jewish books and Torahs some communities were fortunate enough to have written in the liturgical language of Ge'ez.