Termination Regulator for DDR4
To back up a bit, the termination regulator exists to make sure the termination voltage (VTT) is half the supply voltage (VDDQ). The biggest concern I would have is the VTT tolerance on your new DDR4 parts. For the first round of prototypes, I would also put a current sensing resistor to make sure this part isn't close to its design maximum trying to sink current during regulation.