Concrete pour against green board
Assuming that this is a new 4 inches of floor on a ground level structure...

No this is definitely not ok.

Greenboard is mold resistant.  It is, however, still just gypsum with paper over it.

Neither is using pressure treated wood as a barrier.

Why?

Concrete wicks water.  Any water near the area will be distributed to be brought into direct contact with the gypsum or wood.  Gypsum and paper, when left exposed to moisture, falls apart.  Wood, even pressure treated, will rot eventually.

This is why sill plates, which sit on top of foundation walls that can be several feet above ground, are protected by moisture barriers.

You need to put a waterproof (PROOF, not resistant) substance between the new concrete and existing walls, OR lift the walls up (not likely feasible).