The WBS should completely depict the scope of your project that if something is not in the WBS it is because it is NOT part of the project?

WBS and by extension the activities under WBS is assumed to be representing the scope of works.

But in reality it is hard to include everything in the programme and represent by an activity or WBS.

Suppose you had gone through each and every portion of the Scope of works description and with

extensive discussions with experts on the subject prepared a programme with all the activities that is required to present the Scope.

There are still some responsibilities which are included in scope but cannot be represented in the programme.

for example, Interface and co-ordinations , ARE part of your scope but cannot be entirely pictured trough use of WBS or activity.

Design and Build projects may have new requirements which was not anticipated but through extension of contract are part of your scope. Clearly was not in the WBS earlier.

Although, arguably  one can say that all these are included under a higher level of WBS. 

So by default, Scope of work cannot be defined by WBS. WBS only presents a easy to understand breakdown of the same.

Hope I shared good info.

Regards

In this case I think its false