Having the school evaluate for disabilities absolutely doesn't kill submitting results from a private evaluation, and may open the opportunity for that evaluation to be paid for by the district as an IEE at public expense if you get the evaluation because you disagree with the results of the school's disability evaluation. You have to let them know you disagree with their results (you don't, however, have to tell them WHY you disagee) and make the request for the IEE at public expense before you set up the private eval, though.