In my experience for a typical BJT input stage doing this more than doubles the overall distortion of the amplifier. Most of this distortion is third harmonic however due to the nature of LTP inputs. The level is very low indeed comparatively speaking, we're talking about the best case scenario for a class B bipolar amplifier design.
I don't have any measurements to upload right now, all I can offer up is a quote from veteran designer Douglas Self protesting against this sort of thing having seen it featured in an issue of Electronics World which perennially publishes badly designed audio circuits as filler material... Screenshot from his site attached.
View attachment 210922
For JFET/MOSFET inputs you're already going to have much higher distortion than necessary (and a DC servo to cancel the offset unless they're very carefully matched) so I doubt there's any benefit to having a low source impedance in the first place.
RE bipolar inputs, I've consistently found the 5534 and NJM2068 to be the best op-amps for the job vs all the FET devices I've tested so far, although they do have very low current noise indeed. Unfortunately parasitic and more importantly nonlinear capacitances are much higher in FETs which will most likely heavily degrade the distortion at the high impedance, high level, high frequency characteristics that moving magnet cartridges offer up.