It depends on the level of detail in the plan. The article says to delay the plan, not to skip it. The goal of that is to avoid fleshing out the details of part

It depends on the level of detail in the plan. The article says to delay the plan, not to skip it. The goal of that is to avoid fleshing out the details of parts that are not relevant to the current focus (with "focus" being defined as the scope of the current sprint). Of course, you need to know the direction of the project. But spending time on details that you cannot directly validate with implementation, risks both wasting time because of invalid assumptions, and risks wasting time because the requirements may change when you get around to implementing it. Remember that "planning a sprint" gets very deep very quickly. It's not just about setting direction, it's about deciding display names, storage types and UX interactions. The point of the article is that that level of planning should not be done months in advance.