It's not really confirmed one way or the other, to me, as I noted... I've never really noticed the seller list things as "custom" all the time though, as you claim CHEWIE. NOt to say he hasn't, but I know I certainly haven't seen that, especially lately. Just this one figure's listing.
Right now, there's just as many factors to say it's just extra parts put together as there are to say otherwise... I think if there were a rumor swirling to the contrary, I'd be less skeptical.
Personally I'm running with it just as a questionable item right now till it's confirmed. It's one of those things too easily faked not to, I believe. It's basically not the Dewback.

I'm thinking it's odd the hood isn't decorated to match the body glove, that works against it, but I haven't seen anything confirming it either way so for now I think the readers should take it with a grain of salt. Just one of those things that'll either surprise people as true if it turns up at SDCC, or not (and then I don't think most people will really care, as I didn't hear anyone clamoring for these). For now it's a simple "perhaps" though.