I have opened a breakpoint booster box which was the same, all white codes so they must sometimes either make mistakes or just ran out of the green codes and used all white
Edit: Phantom forces was before they started using the green codes? I believe it started with breakpoint
The white/green code card anti-pack weighing thing started with Breakthrough (iirc) and then was applied to all previous formerly out of print sets (Ancient Origins, Roaring Skies, Primal Clash) when they were reprinted. So you can get first-printing packs of PRC, ROS, and AOR with no holos and white codes. All codes in PHF are white and all previous sets with codes had specifically-designed code cards for each set and no variations.