Why do people think that Riot isn't going to do Halloween Harrowings at all?

By now we all now the statement stating that Harrowing isn't restricted to October/Halloween anymore. But isn't the more likely idea behind it is that they want an excuse to tell more of the new history of the Blessed Isles, of the SI Champs, and the involvements of those enveloped by the Black Mist.

You all sound so pessimistic when more likely than not, they want to tell more stories without being restricted by one day a year. Halloween is always going to be that spooky time of the year, so why must the F**king Undead coming to life and murdering people always be connected to a day where kids roam the street in cute little costumes?

Runeterra can still have a connected year like timeline to real life, but why is Halloween connected to the undead spreading to kill fools?