Is This a Reference to the House of God of Alexandrian Jewry Developing into the House of God of Alexandrian Christianity?

The reader will have to be aware that I don't think that the eunuch Origen was the exception in Alexandria; I think he was the rule. I see evidence stretching from the time of Justin Martyr down through to the cross dressing Hilarion/Hilaria that the Church of St. Mark in Alexandria was the home to a faith which took the Egyptian gospel's command that "the two become one and the male with the female is neither male nor female." (Clement Stromata iii. 13. 92) In any event here is the oldest - and most curious - reference to the establishment of a Jewish temple in Alexandria (the story is universally dated to the Tannaitic period i.e. 70-200 CE) :

When he [Simeon] was dying he said to them "My son Onias will serve in my place." Then his brother Shimei envied him, being older than he by two years and a half. He said to him "Come, I shall instruct you on the order of the Temple service." [Shimei] put on him a light gown and girded him with a girdle and set him up by the altar and then said to his brothers, the other priests, "See what this man has promised and carried out for his girlfriend: 'On the day on which I shall take up the office of high priest, I am going to put on your gown and gird myself with your girdle.'" His brothers the priests wanted to kill him [for coming to the altar wearing women's garments]. He [Onias] fled from them and they pursued him. So he went off to Alexandria in Egypt and there he built an altar and presented on it burnt offerings for idols [Tosefta Menahot 13.II.1]

In the Talmudic discussion Rabbi Judah b Ilai argues with Rabbi Meir and states that the roles of the two characters should be reversed. Shimei not Onias was the victim of subterfuge. According to Rabbi Judah, when the priests were about to kill Shimei, he explained what had happened and how Onias had tricked him. The priests then went after Onias who fled to Egypt and built an altar to God in Alexandria.

There are countless versions of this same story including:

Shim'on the Righteous served as high priest for forty years. In the final years he said to them, "This year I am going to die.' They said to him, "Whom shall we appoint as you successor?" He said to them, "Here there is my son Onias before you." They went and appointed Onias. His brother Shim'on was jealous of [his brother] and he dressed him in a gown and a girdle. He said to them "See what he has vowed to his beloved: On the day on which I assume office as High Priest, I will put on your gown and girdle." They investigated the matter, and they did not find him. They said, "He fled from there to the Royal Mountain and from there he fled to Alexandria. He went and built an altar and he recited the following verse "In that day there will be an altar to the Lord in the midst of the land of Egypt (Isa 19:19) [y Yoma 6:3]