It's been confirmed i.e. both my library school friend and an aquaintance who's just finished her MLIS agree - you don't have to do all the readings.
It seems a waste of paper not to read them, but you don't have to. This is because a) you aren't necessarily going to be assessed on it, and b) the professor is going to mention the main points of the module at the next weekly seminar anyway.
This is actually an enormous relief. So many of the readings are frustratingly boring and mind-numbing. It's so hard trying to read them well enough to make notes. Instead, I can relax, knowing I won't really miss anything crucial as long as I turn up to class and listen.
Perhaps I get to watch Zoolander repeatedly after all...