Look, I'm not sure what to tell you except to look into the history of black actors (and in this case, black characters) in the media and relevant media criticism before having this discussion, because if you're seriously trying to use those kinds of strawmen then there's no point in having this discussion. I'm not trying to be mean or dismissive; it's just that the whole context of what I was saying is the long history of film/television/print media's established preference for lighter-skinned, whiter-appearing black people. If we don't share that context, then we'll be talking in circles.
On rereading my earlier comment I should probably clarify that I wasn't saying this hypothetical Fantomah-whitewashing would be done (or has been done?), deliberately, but it's directly playing into that whole problem (which is still alive and well today).