The creator didn't say it was going to be. He said something along a "Disney-style ending", I believe. He didn't say it was going to be more or less extreme than either of the other two films.
Maybe I just mis-took what he said. But there was no "disney-style ending" anywhere to be found when I googled information though.
In an interview with DreadCentral.com, Six said the third film will "make the last one look like a Disney film. We're going to shoot the third film entirely in America, and it's going to be my favorite... It's going to upset a lot of people."
This is quote I was thinking of in regards to Human Cenitpede 3.