This is the last of the DAZ legacy figures.  DAZ would take the new figure, morph the body and rig it to match the previous generation's figure so you could use the clothes from the previous generation.

There was even P4 Vicki, P4 Mike and P4 Stephanie.  They did this for the Gen 3 figures as well. 

V3 to V4 can use V4 head morphs but is rigged for V3 conformers and does not have injection channels.  It also uses V4 textures.