Colorblind casting rarely works in "reverse" because many plays centering around non-white characters feature ethnicity as a central facet of the given circumstances of the story. Ergo, "A Raisin in the Sun" would not work with any cast other than what was specifically called for by Lorraine Hansberry, whereas "Much Ado" holds up, regardless of multi-ethnic casting.
Anyway,
The only people worried about casting a Black actor in a brutish role are those that, THEMSELVES, see Black men in that way. The fact that Billy is Black should have no impact on how his humanity is portrayed and perceived, but since this is America and we are in the throes of PC panic, Mr. Henry's race must needlessly become a centerpiece of the conversation. If the aim of the production is to make some sort of commentary about Billy's "Blackness", I don't support that, unless such an approach illuminates something interesting about us as people AND about the piece itself.
I, for one, view Blacks as individual human beings, capable of any number of virtues as well as flaws. I find it fascinating that, as a character, Billy has incredible complexity, and is a GREAT role for an actor with the acting and singing chops to assail it in all it's beauty AND ugliness (must be said, that the combo of those two skills in great abundance is rare).
At the end of the day, it is not Mr. Henry's, nor anyone else's job, to make you all COMFORTABLE. It is his and everyone else's job to create a vivid and compelling production of a difficult yet classic piece of theatre that is worthy of people's time and money.
(On a side note I also find it amusing that people are assuming that Mr. Henry is the "best" actor that auditioned for the role, rather than the one producers thought would be most marketable. Surely there are other leading men in New York that could sing and act the pants off the role, who didn't even get into the room to audition. In fact, we don't even know if Henry auditioned at all--he and Rudin worked together on "Shuffle Along", presumably there was already a relationship there, perhaps some conversations took place. Who knows? I don't. You don't either.)