So it is the individual inspector to say if it is okay and the code not to specific.
I guess if you want your project to pass inspection you must do what the AHJ wants.
Well yes, but sometimes it may be worth it to argue; you might change their minds.
In your case it seems the question is not the definition of 'accessible.' The question is if there's a requirement that junction boxes be accessible. I don't know of any such requirement. And there is definitely no requirement that they be 'readily accessible.'
If he is saying that the boxes must be 'accessible', first ask him for where the code requires that. Then point out to him that a junction box is just part of the wiring method. The second definition of "Accessible" is '(as applied to wiring methods)', and it says 'capable of being removed or exposed without damaging the building structure or finish'. Temporarily removing a solar panel to get to a box does not damage the building structure or finish.
If an AHJ wants more access than that then he is way off base and that should be politely pointed out to him.