1) Naftoli, the Gemara Yoma 5b asks a similar question to yours. The Gemara asks how were the Cohanim dressed in the time of the Mishkan; in what order were the Cohanim's clothes put on:- was Aharon dressed first and afterwards his sons, or was it first his sons and afterwards Aharon? The Gemara asks "what difference does it make in which order the clothes were worn; this is all past history?!" The Gemara answers that we need to know in which order it happened in order to explain the verses in the Torah.

So we can say similarly that we need to know the history of the korbanos in different periods in order to understand various passages in Tanach.

2) See also Chulin 17a where the Gemara asks what was the Din if somebody killed an animal without Shechitah before the Bnei Yisrael entered Eretz Yisrael at the time of Yehoshau bin Nun, but did not eat the meat until they had already entered the Land; does the heter of eating non-slaughtered meat only apply before they came in to Eretz Yisrael or does it apply to any meat slaughtered in Chutz LaAretz, even after they entered? Rashi writes "Drush v'Kabel Schar"; we receive a reward for the Mitzvah of learning Torah by asking this question. Rashi writes "we must establish the truth of the matter even though it has already passed by".

3) The Rosh in Chulin disagrees with Rashi. However I would like to suggest that Rashi's source is from Devarim 32:7

"Remember the days of the world, understand the years from generation to generation. Ask your fathers and they will tell you, your elders and they will say to you".

Rashi understands that there are always things one can learn from delving into previous Halachic questions and striving to know the truth of Torah.

Chodesh Tov

Dovid Bloom