Yes, that's EDIG's claim. But it's not one that accused infringers will agree with. Thus it becomes a point of contention in court.

EDIG (more accurately DM) needs to be be able to demonstrate beyond any doubts planted by a defense — to someone like Judge Krieger, or a jury if the case ever gets that far — that their patents are indeed "fundamental" and cannot be circumvented by a design workaround.