Come to think of it, i think they might feed cows soybeans.

I know that when making butter it matters a whole lot what the cows were fed. If cows were 100% grass fed your butter would be quite soft, but if you make butter from cows that were mostly fed with corn or (in some cases) (additional) palm oil your butter will be hard as a rock.

I think it matters a lot what the cows were fed and what was in it.

Mostly typical media hysteria what we're discussing here on some bleeding edge science with 1 paper and no peer reviews. It's what media does to sell ads.