That's my understanding as well. Rather than ramping the power output up or down with demand, you keep it at a constant power level and basically use the molten salt loop as a battery -> store energy when you're outputting more than is required, draw energy from it when you need more that you are producing.

The multi-gigawatt nuclear installations are typically supplemented by natural gas "peaker" plants to deal with higher demand than the reactor output, but lose any extra power produced.

If I recall correctly, the naval reactors (submarine and surface vessels) are the only ones that are designed to rapidly shift their power output.