Emission rates within MOVES are stored by "regulatory classification" rather than source type. If you ask for only one source type within a classification, MOVES (internally) calculates emissions for all source types within that classification.
MOVES then "filters" the results so that your output contains only the source types you asked for. Asking for one source type or all source types will not affect the answer for any single source type result.
If you want the results to label the source types, you must select them in the Output Emission Detail panel of the MOVES graphical user interface (GUI). Otherwise, even if you only selected a single process and source type, those fields will be NULL in the output tables.