This is the only thing I'll say on this matter, though I think this is all kind of stemming from the fact that you're assuming that casting a minority actor means you're trying to "accomplish something."
Let's look at this from a casting director's perspective, I'll use a casting call I held a while back as an example. I got over 100 auditions for the role, and I chose a Malaysian actor. Not because the character was Malaysian, or that I had something to prove, but because they were right for the role. They understood the character, and incorporated their understanding into the performance accordingly. If I was trying to prove something, I could flaunt the casting decision. But that's not the point. The point is that they were right for the role.
In Pinnochio, we know how the Blue Fairy is depicted. We know what she wants, what she's like, etc. Some random white actor isn't necessary to properly convey that. Characters go through human emotions and experiences. Any actor is capable of harnessing that. Minorities shouldn't be barred off from these roles, especially when this is a NEW interpretation of the character. What's stopping the Blue Fairy from being black? At the end of the day, they're still the Blue Fairy, after all.