You may have provided your own answer to the question. The CCLA has taken this approach to a number of pieces of national security legislation, arguing that a specific reference to the charter should always be built in. I can see its symbolic value. I also think, in strictly statutory terms, it's unnecessary, because the charter is the law of the land. It really is a matter of symbolic politics and up to parliamentarians to decide whether they feel that's necessary or not.
On October 24th, 2017. See this statement in context.