Not having the read the book, what is #4 about? Are deadlines not a necessary thing? Don’t most SW teams use sprints to push out features on a regular basis?
#4 states that there's a tradeoff. If you are working on a project, and you can tell that as designed the project will be finished a month late, there are two options: 1) move the deadline or 2) Reduce quality/features. The example used in the book is a cook making omelettes. If it takes 5 minutes to make an omelette and the cook promises it in 4, at minute 3, the cook can either tell you it's actually going to take 5 minutes or the cook can turn up the heat and make a crappy omelette. In SW terms, SW teams are working on a project that is estimated at 8 sprints. At week 4, they're currently on track to finish it in 10 sprints. The SW teams can either remove features, reduce quality (maybe they skip writing tests or code reviews or decide to use a "hacky" solution instead of the "right" solution) or move the deadline.