The service advisor mentioned the recall and of course I asked 'so how come I've not been contacted about it and only know when I bring it in to have the problem fixed?'. His reply was that in Canada the privacy laws mean that BMW have to ask the government for drivers addresses and that takes a long time (rather than using their own records?...) and it often happens that people bring their cars in before BMW have had a chance to contact them.
I don't know if this is true or not (I'm not Canadian and have only been here a year) but it sounds silly to not do a recall for those reasons: what if the issue was safety related?
Anyway, that's the answer to the question, unsatidsfactory though it sounds.
Peter T