Clearly, the audience can tell that *something* is missing in Act III.

Whether it was cut or the last act of the game is unsatisfying for the community is almost irrelevant. The narrative threads were set up well. Extremely well. But they're not paying off in the current iteration.

My guess, and it's just a guess, is that there are writers on the staff who had to compromise some narrative vision for one reason or another, and that turned out to be a mistake.