There is a lawsuit in California that is attempts to get complex trauma classified as a disability and an area of eligibility for 504 plans and special ed. It's winding its way through the courts.
Is Trauma a Disability?
I've worked with students who are traumatized to the point of it affecting their learning and for whom special ed services would be appropriate.
If they and their families had adequate access to mental health services to help deal with the trauma and accommodations through a 504 plan, it might not be necessary to receive services through special ed. At least this would be likely for a good number of students. Unfortunately, mental health services are lacking for so many people suffering from the effects of trauma.