I'm sure it's not, the problem is that the OS4 Pro (like the OS3) has a proprietary DVSI chip which implements the AMBE codecs to allow for cross-modes between DSTAR and DMR/C4FM but not codec2.
I would hope to see M17 support in a new openSPOT device, but I can't see how it could be included in the current device because of the hardware design.