Well since the game is now very losely liked to the lore of the world, the best corse of action is to dettach any links with our own holidays and those in the runeterran universe. Harrowing has different feel in comparison to Halloween. Halloween is celibrated as the end of the season harvest. The seasonal transition from a somewhat live fall to a dead winter inspired the myth where the world of the living and the dead both intertwined during this day. In Orthodox Christianity, on this day every saint is celibrated, aka spirits for the western chirches. But only during the start of the 20th century did Halloween get its typical celebratory style trough capitalist consumerism.
Harrowing while in its origin was nothing but a coockie cutter Halloween for the game (as with all the lackluster pop culter references and stereotypes of the eairly lol lore pre retcon), it began having its own feel with the release of more Shadow Isles champs such as Hecarim, and the release of both Elise and the reworked Twisted Treeline, which solidified Shadow Isles as a place. But the true change was felt last year, with the introduction of the Black Myst as a world building entitie (I also have to add that the harrowings all of them didnt happen each year, rather they gradually started to happen more frequently and more deadly). Harrowing was not just a holiday where the spirit and living world intertwined, it was now an omens to a larger threat that many thought to be a tale told by crazy street performers. While the Black Myst is the object with which to enact the ripping of the souls from the bodies of the living, The Harrowing is the whole atmosphere, the threat, the despair, and the embodiment of Morderkaisers will to rule Runneterra once more with his undying legon army.
You can not call it a holiday anymore, it is something far more threatning as a concept and just spreading it during the time of our holiday not only does it make no sense in terms of the lore(cause how can you just bound such a ting to one day every year, you cant tell Morderkaiser when he should attack you, he attaxks when he pleases), it also disservice to such a thing as the Harrowing to be even bound anymore to something pathetic and non threating as our capitalist made holidays. Sure Halloween should still happen each year Halloween themed skins, just like Xmas and Chinese New Year, but they should not be tied with the holidays or events within the lore, which got its own life now.
