I see your point. The DC from the solar array enters an inverter after a disconnect. The inverter is "Grid tied" and can not generate power once main power to the building is removed. Does the solar array disconnect count as one of the 6?
The answer is, it depends. If the solar DC power never enters the buillding, I would say no. But, To inform the fire department of possible hazards required 230.2(E). If the DC enters the building, well, under 230.2 "Different Characteristics" applies and allows the additional disconnects with Identification. Disclaimer: Local jurisdictions may have rules for this, so as always talk to your local AHJ.