The Mishna at the beginning of Yoma relates the machloket between Rabbi Yehuda and Chachamim as to whether the Kohen Gadol should have a second wife available in case the first one dies. While the halacha follows the opinion of the chachamim, as stated by the Rambam in HIlchot Avodat Yom Hakippurim, wouldn't it have been known during the Bayit Sheni period as to whether indeed the Kohen Gadol had a second wife lined up? This machloket is not the 'normal' machloket, but wouldn't the metziut have been known? Obviously, the machloket takes place after the churban, as Rabbi Yehuda, musmach of Rabbi Akiva, lived during the time of the Bar Kochva revolt.
One approach may be that the mishna is speaking of hilcheta de-meshichah, when the Bayit Shelishi is built. Any thoughts?
One could ask this question on a number of different mishnayos which discuss different aspects of the service in the Beis Hamikdash, since for example Rabbi Tarphon and Rabbi Yehoshua as well as Rabbi Eliezer Ben Yaakov still remembered the Beis Hamikdash (see for example Erchin 11a a story about Rabbi Yehoshua, Kiddushin 71a, Yerushalmi Yoma 3:7 about Rabbi Tarphon.) Since these Tannaim conversed with later Tannaim and surely related the manner of the service, how are there disputes about it?
It is possible to contend that the Tzedokim had a lot of influence in the Beis Hamikdash and especially in the matter of the Kohen Gadol. This is evident from the mishnah (the need to make the kohen swear that he will do the avodah properly) and from other sources- we see that there were 318 kohanim gedolim during the Second Temple which implies that they were not tzadikim who were meticulous about halacha.
The Tzedokim would not have recognized the need for another wife as they would understand the term Beiso as referring to a family or a house and would not have said Beiso zo Ishto. Thus it is possible that they did not maintain this custom but Rabbi Yehuda still maintained 70 years after the destruction of the Temple that it should be done in accordance with the drasha he brings.
Yoel Domb