More than 85% of soy grown is for non-human animal consumption. Animal agriculture in Brazil is the leading cause of Amazon deforestation, likewise, animal agriculture in Argentina.

I'm not even sure if you've read the source you've given as it states the same.

Not to mention that most soy humans consume is non-GMO (which excludes practically everything from Argentina and Brazil), and that soy is grown in China, and for example in suprisingly large quantities in Serbia. So it's not even necessary to cut rainforests.