The change comes straight from AMD, this is not a case of AIBs renaming parts. The official Radeon RX 560 product page now shows this model can have 896/1024 stream processors, whereas an earlier revision of that page listed 1024 stream processors. The version with 896 stream processors is basically a rebrand of the Radeon RX 460, and is not as fast as the full Polaris 11 GPU based RX 560. The full Polaris 11 GPU has 16 CUs, whereas this cut-down model has just 14 CUs.
Unfortunately, these cards aren't marketed as Radeon RX 560D. So as a buyer, it can be hard to know which card you're getting. German tech site Heise says Sapphire sells its 896 and 1024 stream processor Pulse Radeon RX 560 4GD5 video cards under the same name, but with different serial numbers. Basically, a consumer-unfriendly mess that could have been avoided.