Because once you’re in, that’s it for two days. The only place you’re going outside the hotel is Star Wars Land, which you’ll enter into through a private special entrance. It is an all immersive, all inclusive, VERY EXPENSIVE, experience.
It only seems to happen with one particular poster, which means more than likely, @scrappinginontario has the other poster on ignore and is unable to see their postings.
TSL opens this Summer. Star Wars is opening "sometime" in 2019, probably not until later in the year. If you're worried about crowds, stay away from the week before Easter you mentioned.