Trust me, i 100% believe you because this is exactly what i have seen in certain Somali communities first hand (In the Netherlands and Sweden). I too have heard from some of my family members in Norway that many of the special ed classes are filled with Somali children and my online Canadian-Somali friend from years ago have said the same thing regarding many Somali children being diagnosed with autism.
The thing that i find to be the most suspect is the fact that some of the researches/articles that are talking about the link between war and autism and why refugee children are thus more prone to being autistic, is the fact that you don't see this prevalence in other refugee communities like Iraqis, Syrians, Burmese, Nepalese, Rwandans etc. Why does this explain on why Somali children are more at risk for not developing mental illnesses in general but not in other communities? It doesn't make sense to me in that regard.
But nevertheless i'm atleast happy that those kids get the help and attention that they need, especially in schools, so they can properly function in society.