That is not what R Moshe Alshich says. He doesn't say doesn't say "our Rabbis of blessed memory". R Moshe Alshich uses a common abbreviation: R"ZL. The usual assumption would be that that's what it means, but the abbreviation also stands for *my* Rabbis of blessed memory...................'

Eli..........R. Alshich's own writing is that he meant his commentary to be literal.. And rabbis, whether "my rabbis" or someone else's rabbis, means that he learned from their beliefs,  conceivably, before and after Rashi's claims. I think you want truth but then you are policed to be held with-in a strict code of modern rabbinical POV. And if the ancients made some serious mistakes, then it would effect a lot of thinking along the same lines. R. Alshich was in disagreement with Rashi, otherwise he would not have made his commentary known. Call it hyperbold if you want but there was and is a difference of Jewish opinion, even today, with Rashi's Isaiah 52-53 commentary