Though I don't think they would make this change, my D2 drivers are genuine M2 versions (gold label with the correct part number). Is there any possibility that they would label the M2 version different from the PA version of the driver?

I have not made the phase test on the D2 so I'll take you at your word that positive on + makes an inward motion. That would be odd for JBL in the "modern" era. While that was true of JBL product into the '90s, they did make the switch to conform with others such that positive voltage on + would be an outward motion. Those drivers that were directly replacement to legacy drivers would retain the original polarity (e.g. 2446, replaces a 2445 so it keeps the legacy polarity, likewise on a 2241 replacing a 2440 for a cone driver. A 2242, on the other hand, didn't have a legacy driver to match to so it adopted the new standard).