Here's my short answer: Just like wheat, dairy, shellfish & fish, tree nuts, peanuts, eggs....soy is also one of the top 8 food allergies. Many people have a problem with soy. If you have a problem with soy you would have noticed either right away (IgE response) or through a delayed response-just like wheat and dairy.
Soy is not for everyone, which is why I suggest you watch your reaction to it and any other top 8 food allergens during the luteal phase or get tested for antibodies against soy to be sure. Soy happens to also be in everything processed but will be on the label if it's included.
I am also not a fan of taking large doses of soy "isolates" for menopause symptom relief. And two cups of organic soy milk doesn't contain enough isoflavones to cause hormone alterations in humans.
There are other dairy substitutes besides soy for those who want or need to avoid dairy and/or soy.
Nut milks- Almond, hazelnut (as long as you don't have a problem with nuts)