Investigators are the ones that put in the place holders. The conference is supposed to drop the place holder if nothing is received by the submittal date. LL and Dr. B likely do not have the time to run around in the background to make sure all place holders are taken down when nothing comes in as they correctly assume that because nothing was submitted. It is standard procedure that the placeholder be taken down, and so busy investigators assume that it will be.
Really, they should follow through on what they started. Why? well, to put a stop to all this BS going on now. Just common sense in my book.