Not sure about that. I do know that about half of LPs pressed at the time, maybe still, are reversed phase. Most of the time, it doesn't matter to the sound, but on certain LPs, you will notice weaker bass. Reversing polarity, either at the cart or the spk terminals, should solve the problem. I haven't experimented with this, but my phono reverses polarity anyhow and I haven't had any problems.
If you do try, let us know.
If you do try, let us know.