Distribution-side voltage regulation and Low voltage ride through (LVTR) curve
If you look into this draft: P1547/D7.2, Nov 2017 - IEEE Draft Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces, you will notice on section 5.4.1 that "Category B DER shall, as specified in Table 6, provide a voltage regulation capability by changes of active power."
So I guess the answer to your question is that the industry is still adapting to this new control paradigm.

Here is a paper that considers active-power-based voltage control: Autonomous Inverter Voltage Regulation in a Low Voltage Distribution Network