What must be matched between a SUT and the cartridge is the SUT gain to the cartridge output level, this is the main issue and not impedance loading.Any SUT with the rigth gain can works with any cartridge with the adequated output level it does not matters its impedances.
This is at best misleading. I agree 100% that the sole purpose of the turns ratio is level matching. It is best to match a SUT for both step up ratio and cartridge impedance. Taking the two extremes of a 2Ω and a 40Ω, a 2Ω cartridge feeding a SUT designed for 40Ω will have bass response down to the single digits and show a pronounced resonant peak at some point (hopefully) above the audio range. Going the other direction and using a SUT intended for a 2Ω source with a 40Ω cartridge will result in inadequate low and (possibly) high frequency response.
dave