I'm envisioning 4 scenarios.
1) Was a noisy day at the office when Swen said "We need to cut a few levels of lair beneath phantom forest" and person who cut said content only heard "Cut lair beneath phantom forest"
2) It was a busy day at the office to get everything complete and content locked down when person in charge of cutting the content pressed the wrong button and deleted everything without noticing.
3) They really decided on purpose to cut the whole thing for whatever reason instead of just the few levels.
4) The dog ate it.
I like your option 4, as some dogs will eat
anything, but regardless of which of them are the case, if any, it would have been reasonable to make a short kickstarter update stating which content was cut for the release and the plans for it. No need for a video, just a few lines that would be easily searchable since many kickstarter backers just skim the text of updates for major headlines.
After all, lacking clear communication on such a point, the risk is that some gaming website takes up the "What happened to X, which was promised in the kickstarter? They took your money and being independent they controlled their own release, and yet didn't deliver" story, and pretty soon you are talking damage control rather than raves for a game where the core game is pretty awesome, and the major gripes apart from lair/companions seem to be the UI issues of poor inventory management, a few missing hotkeys for action bards, and an annoying way of doing crafting.
