I don't see why they would not consider speech other than them thinking he is still young and the other testing they did doesn't support an issue is there. My son did not speak until he was 3 1/2 or so but their testing prior to that pointed to the fact he was able to, but he just wasn't ready yet. Also he had the ability to say a few words before he stopped speaking.

The other option you have is to have an outside evaluation done by another speech therapist or even a neurologist and see if the come back with something different.

I wouldn't panic right now because your son is stil young and he might just start speaking out of nowhere and surprise you. Sometimes children have to feel comfortable before doing something so it might just be a wait and see.