So it's confirmed by Dan himself on discord, Hatty is NOT the narrator! This was actually stated back in 2017, with him saying it was originally meant to be Hatty, but stamper wasn't fond of the idea and so the narrator is just some guy.
If there's any pages that still wrongly refer to the Narrator as Hatty, either let me know or please do update them to link to the Narrators' new, own remade page! :)