Output level would not be a worry with the 2M Black and the ZP3. Cart output of 5 mV  -> 42 dB/125x gain = ~.63 V into the ZTPRE. Phono cartridges can (and do) easily output 2x or more than rated spec, so with louder music and/or higher cutting levels it could be 1.25 V or more out of the ZP3 and into the ZTPRE. The specs for that preamp don't include gain, but even assuming 6 dB (I'm pretty sure it's more than that) it would output 2.5 V or higher at full volume.

Another thing is that the ZTPRE comes stock with balanced XLR inputs only. However, it does have option for an additional single-ended RCA input, which is then properly transformer-balanced, to feed the differential preamp. This would then accommodate the RCA out from your phono stage.

Addendum:

I just remembered a chart that Steve provided wherein it was shown that the CSP3 preamp output 10 V from a 1 V input with input level control and volume all turned to full. So 20 dB gain in that case. The ZTPRE is basically two CSP3 in differential operation. But they both spec as 30 V max output, so I'm not sure if the gain doubles or not. Either way, both of those preamps could easily overwhelm the input of any amplifier out there long before reaching full volume, while being fed from almost any MM cart via phono stage.