The Honeywell (Garrett) TPE331 has a negative torque sensing sytem which will indeed partially feather the prop if a flameout occurs. Depending on the installation of the airframe manufacturer this can be backed up by a manual feathering procedure or a full autofeather system.
Regardless, being a single-shaft engine, it is necessary to lock the blades on flat pitch during shutdown to prevent excessive load during a subsequent start.
If the procedure to do this is not instigated by the crew (during an unscheduled shutdown) then the prop will go to the fully feathered position when oil pressure is lost.