In women, Soy also mimics estrogen. So if you indulge in a soy filled meal, and then dont for a few days, the body can see this as estrogen fluctuations. Being a guy, I have no experience with this but have read it quite a few times in different places.
One thing that is for sure: All hormones play tug of war with each other, so its best to keep them as balanced as possible.
I think the difference is between fermented soy and um-fermented soy. - something for you to goggle.
Soy disrupts the absorption of thyroid meds, T4, Like Levthyroxine,Synthroid etc, Best Regards FTB4