In the Material Dialog box the Units dropdown filters the viewable units for the entered material properties. 
Is the Model Type dropdown also just a filter to show properties associated with that model type?

OR

Does the selected dropdown cause filtering of available materials when performing a simulation study?

   In Other Words will 6061-T6 shown in the following image not be available when performing a structural study in simulation because it was saved on "Plasticity -von Mises" and that model type is only available in nonlinear and Drop test simulations?

2020 SOLIDWORKS Help - Material Dialog Box - Properties Tab 

2020 SOLIDWORKS Help - Material Models