Hex Maniac - Some sort of Halloween Event? Are you the one to find out?

are they alluding to the elevator ghost girl? and the sign in the train station

In Lumiose city, there is a rumor that you may encounter ‘IT’…

(Directions on how to get to the haunted building)

I asked Hex Maniac-san.
(What kind of place is this Lumiose building?)

Near Laverre City is the old man’s Scary House.
The old man of the “Scary House” told me a spooky story.
In the middle of this story, mysterious girl and similar serif(?)… And you won’t get to ask at all.
That old man… seems to know something!

Just what on earth is that girl?

Hex Maniac Guide
Reality Pokemon Horror Spot

When you get off the elevator on the 2nd floor, “IT” will appear…
“You shall meet only this once…”