The history of the Mansion with infighting and back-and-forth between Walt and various imagineers on whether to make this scary or silly and what the story is, is well documented, e.g., the raven was supposed to be hosting your journey, but then, nope. And so, we have a raven just chilling out in a bunch of scenes adding nothing to the narrative. Lots of hands have tried to impose a plot including the Eddie Murphy movie. It's just a montage of haunted house scenes. A really good one. But the overall IP doesn't have a cogent narrative that accounts for all the scenes.
Imagine if Disney had made a really good kids' silly-scary haunted mansion movie long ago (real life or animated) and then the Haunted Mansion was based on that? It would have made the ride better, IMO.
The MK version of PotC lacks any hint of a portal since the queue begins with you being in piratey times. The drop isn't associated with anything related to a narrative or anything at all. If later refurbs killed the original original story... oh well. I don't remember the portal story from my youth.
Here's an original IP ride: Superstar Limousine. Let's have more of that!