I would guess this is a by-product of the PacHy using the strippo Pacifica 'L' as its basis (as was stated by the PacHy chief engineer in a podcast video). It would go a long way to understanding the inexplicable absence of things that are standard on the gas models (particularly the Limited).I wonder why they continue to piece-meal options to the Hybrid. My work fleet got a '17 Hybrid when they came out, fully optioned and I was shocked that there was no memory seats and Homelink. It took two model years for both of those to appear. Still no HIDs.
Unfortunately, the engineer did not state the 'reason' the PacHy is based off the Pacifica 'L'. I'm going to guess it's due to the basic architecture of the 'L', i.e., the absence of Stow n'Go seating on that model (the 'L' has a bench middle seat). It's just simply much easier to convert a non-Stow n'Go Pacifica to a PHEV than one of the higher-trim models. But the trade-off is some of the included features of the upper-trim models end up going missing, too.