The need or lack of need for capacitance loading has nothing to do with cartridge output. However, MM cartridges sometimes do sound best (flattest frequency response) with some added capacitance between the signal carrying wire and ground, and MM cartridges do tend to be higher in voltage output than MC or MI types. (One of those TRUE, TRUE, UNRELATED situations.) But MM cartridges benefit because they have much higher inductance than do MC cartridges, typically 1000X more, not per se because of the signal voltage they put out. Typical MM cartridges have inductance that measures in the hundreds of milli-Henries, whereas MC cartridges have inductance that measures in tens of micro-Henries. Conversely, MC cartridges are more tolerant of variations in capacitance, up or down. Adding capacitance to the load seen by an MM cartridge moves the resonant frequency up out of the audio frequency range, sometimes. Whether to do it and how much to add is also a function of the load resistance you choose to use. For example, 47K vs 100K vs something less than 47K. You have to take this on a case by case basis using data supplied by the cartridge maker. You need to know: load resistor and cartridge inductance, to calculate optimal C.
But to answer the basic question: The need or lack thereof for capacitative loading has nothing directly to do with cartridge output.
But to answer the basic question: The need or lack thereof for capacitative loading has nothing directly to do with cartridge output.