when Rashi says that Yaacov avinu did not die there are numerous mefarshim that explain what it means. There is no mefoiresh saying that he is here with us physically. And yet i heard a Chabad rabbi claim that Rashi said that Yaacov is with us physically; that is a lie.
I guess it’s not just Qwerty who is arrogant about his ignorance.
Rashi (Taanos 5b) explains יעקב לא מת literally.
והאי דחנטו חנטיא סבורים היו שמת – they embalmed him because they THOUGHT he was dead.
נדמה להם שהוא מת אבל חי היה – it SEEMED to them that he was dead, but he was alive.
Maharsha and others ARGUE on this pirush, and explain that his body did die.
This is the classic understanding of their argument, not unique to Chabad. Check any Artscroll.