I don't see any of this covered in the second or third article (apart from a comment in the second article that provides some additional interesting details on

I don't see any of this covered in the second or third article (apart from a comment in the second article that provides some additional interesting details on this hypothesis). There may be a generational effect at play, causing the symptoms to be more pronounced in the offspring of the high margarine cohort. Certain interventions effect second and third generation offspring. You can induce sterility in the third generation by an intervention in the first generation for example. That being said, canola oils and soybean oil are more used than ever.