I don't get why the RPS author is so skeptical. PDB files are fucking gold for reverse engineering attempts. They practically allow those efforts to jump 90% to the end.
The only way this doesn't pan out well for modders is if this new group is lying or just never releases the builds.
This could open the door for something like OpenMW but for New Vegas, and since Bethesda has just been updating this same engine forever, it may assist with other titles as well (but more indirectly).