Rather than an authority, he is an example of the view held by many Jews, including the source you provide . They hold Jewish commentary as an authority, rather than the inspired Scriptures that Jesus championed.
The Jews believe that their scriptures are inspired by God and interpreted by Jewish authority. Jehovah's Witness view scripture as inspired by Jehovah with interpretative authority claimed by Watchtower. Both interpretations come from humans.
What is disputed is the actual interpretation.
What Will the Mashiach (Messiah) Do?
Before the time of the mashiach, there shall be war and suffering (Ezekiel 38:16)
The mashiach will bring about the political and spiritual redemption of the Jewish people by bringing us back to Israel and restoring Jerusalem (Isaiah 11:11-12; Jeremiah 23:8; 30:3; Hosea 3:4-5). He will establish a government in Israel that will be the center of all world government, both for Jews and gentiles (Isaiah 2:2-4; 11:10; 42:1). He will rebuild the Temple and re-establish its worship (Jeremiah 33:18). He will restore the religious court system of Israel and establish Jewish law as the law of the land (Jeremiah 33:15).
Reference: Mashiach: The Messiah
Some Jews were at the time of Jesus, as you have pointed out, convinced of a Christian interpretation of the OT, but it still conflicts with their own scripture explained above.
Modern Jews often regard Christians to have hijacked OT scripture and imaginatively extracted bits to misinterpret for their own ends. Inconvenient details have been ignored by Christians and other NT believers as you did when I first pointed this out to you.
