I've read a lot of fire service reports related to PV systems and attended a lot of training and never seen or heard a reference to the scenario you are describing. Wild fires could burn through a PV power plant, but the fire service isn't asking for rapid shutdown for these ground-mounted systems, some of which shelter goats (in the sense that the have goats on site to keep the weeds down.) Fire fighters want rapid shutdown for roof-mounted systems on homes and businesses.
New Code requirements aren't handed down from some infallible entity. They are developed by industry stakeholders and put through a committee-based sausage grinder. The result is always open to misinterpretation.
In this case, you can learn a lot about the intent of 690.12 by reviewing the CAL FIRE guidelines and then seeing how these recommendations are subsequently codified in the I-Codes as well as NFPA 1 and NFPA 70. This 6-year conversation (starting in 2008 and leading up to NEC 2014) is exceptionally well documented. The scope of the conversation is clearly defined at the outset.
4.0 NON-HABITABLE BUILDINGS
This guideline does not apply to non-habitable structures. Examples of non-habitable structures include, but are not limited to, parking shade structures, solar trellises, etc.
5.0 GROUND MOUNTED PHOTOVOLTIAC ARRAYS
Setback requirements do not apply to ground-mounted, freestanding photovoltaic arrays. A clear brush area of ten feet (10’) is required for ground mounted photovoltaic arrays.
I have never seen or heard anything that suggests the fire service has changed its opinion and now wants rapid shutdown for stand-alone solar carports or ground-mounts.
It seems to me, that if a Fire Marshall or other AHJ wants rapid shutdown at a solar canopy, they should also require complete fire alarm and sprinkler systems. How can you logically apply one set of standards and not the other?