Not necessarily, no. The curricular materials in the base curriculum are intended to work for a variety of different school contexts, including different number of weeks, period lengths, and most importantly, different students. There are many reasons why it might make sense to add an activity or resource, remove one, or even add or remove a checkpoint. Teachers should exercise their judgment, using the knowledge of their students. You may even find that you know of an activity you think will be more valuable to students than the one that’s there. By all means, make the curriculum work for you and your students - we do not have a monopoly on expertise!