The IU has flat out refused any IU preschool placement for him as they don't have the right fit. I guess since preschool is not officially a required grade they don't have to provide anything?
My understanding of IDEA is that your son's right to FAPE under IDEA started when he turned 3.
Mana is correct. As a child with a disability served under an IEP, they have a FAPE obligation. It is for the whole team, including parents, to determine what's appropriate (not the IU unilaterally). But once that determination is made, the child has a right to that appropriate education.
Have you gone back to the IU with your concerns?
DeeDee