I would posit that when the issue arose they wanted to go from "Problematic" to "NOT Problematic", instead of only LESS so. And the identity of Nemesis was already established as a prior form of the character...unless the Nemesis story itself was an internal AOA retcon. I don't recall the chronology of the backstory reveal but the name Holocaust lasted for the duration of the crossover for certain.
And they eventually got to the GENOCIDE naming when the character turned up much much later. Although the revel of Famine/Autumn as his mother was all kinds of ICK.
https://marvel.fandom.com/wiki/Willi...on_(Earth-616)