J189 phones labeled as J189 D01B use version 4 hardware. That hardware uses a different chipset from previous J189 phones and therefore requires different firmware. The firmware, and updated J100Supgrade.txt to install that firmware, are part of J100 R4.0.12.1 or high firmware.
If a J189 D01B phone is attached to an IP Office that is using a lower release of firmware, the J189 D01B will run using its factory installed firmware.
If you are using IP Office Release 12, the J100Supgrade.txt file instructs the phones to load latest firmware if needed.