Star Ocean 3 pulled the same [parasitic bomb]. Damn I hate that.
"Hurrrrr your universe is actually an MMORPG, nothing ever truly happened or mattered!"
This is a big kick in the face of people who enjoyed prequels and makes sequels incredibly silly.
Actually, Monkey Island 2 just pulled a cliffhanger, the "you have been experiencing a fairytale all along" bull was just LeChuck's curse. They said so in a small scene after the credits. They planned to have a sequel right after that, but that didn't happen until years later, and it was pulled off (rather well I might add) by a completely different team.
Now, YEARS later, Dave Grossman met with Telltale, and told them what he originally meant to happen in the Monkey Island canon, while still keeping the Guybrush/Elain relationship alive (which he didn't want to keep, but worked around it). And the franchise is finally being taken in the right direction once again by the company formed by one of the 3 original MI creators.
So, all's well that ends well.