It might be the case that endocrine disruptors may be increasing the likelihood a person is trans, but what you are proposing is almost certainly incorrect and would not work. Using sex-aligned hormones to cause a person to become cisgender is sometimes tried and does not appear to be effective, and I am not aware of any evidence that transgender people's pre-transition hormone levels are substantially lower than their cisgender peers. Also, this theory would suggest that eunuchs, self-identified men who voluntarily undergo gonad removal, would generally come to identify as women, but this is not the case; Similarly for men who have their testosterone suppressed as part of cancer treatment.