The Midrash says that, in the messianic age, all sacrifices will be discontinued, except for the thanksgiving offering. רַבִּי פִּנְחָס וְרַבִּי לֵוִי וְרַבִּי יוֹחָנָן בְּשֵׁם רַבִּי מְנַחֵם דְּגַלְיָא, לֶעָתִיד לָבוֹא כָּל הַקָּרְבָּנוֹת בְּטֵלִין וְקָרְבַּן תּוֹדָה אֵינוֹ בָּטֵל [Vayikra Rabbah 9:7]
But the Rambam says: The King Messiah … will build the Holy Temple and gather the dispersed of Israel, and reinstate all the laws of the Torah as before. The sacrifices will be offered, and the Sabbatical year and the Jubilee year will be instituted as outlined in the Torah. [Mishneh Torah, Laws of Kings 11-12]
So, what is the mainline thinking about sacrifices in the Messianic Age?