Just finished Monkey1, and it hit me the way the cannibals and Herman talked about the giant monkey head, like it was an old attraction that had either fallen from popularity or was just in disuse. The cannibals tells you that they don't enter into the monkey head anymore and one of Guybrush's response could be "did management shut you down?" or something along those lines, and they DO actually talk about the giant monkey head being a big tourist attraction before LeChuck started using it as his "secret" hideout. There are also the little souvenirs for tourists in front of the giant Monkey head, as always, and Herman tells you that he entered the head himself many years ago.
So I don't know if I'm reading too much into it, but I think it's a neat interpretation.