On what basis do they follow the IAS disagree procedure, and not the procedure in emergency AD 2018-23-51? KNKT's preliminary report says the prior flight, Lio

On what basis do they follow the IAS disagree procedure, and not the procedure in emergency AD 2018-23-51? KNKT's preliminary report says the prior flight, Lion Air 34, was not airworthy due to continuous stick shaker activation. Further, that flight expressly requested a much lower altitude, citing control problems for that request. Neither are normal.