Wow -- I can't believe they're doing this. It's incredibly awesome, but I'm baffled nonetheless. Off the top of my head, this is only the second time that we've ever had an homage to a Japanese exclusive character show up in the main US/Hasbro line. The first being Longrack who popped up as an homage in the Cybertron line. I'd consider Black Shadow pretty obscure though to most U.S. casual fans. Not only is this a great choice for an homage, it's the 100% perfectly logical choice.

Are these the only two? Can anyone think of any other Japanese exclusive character that got its first appearance in the US/Hasbro line as an homage?

It'll be interesting to see what his name is.

If they don't do Black Shadow, I wonder if they would use "Sky Shadow" instead since that's a name they've used a few times over the years.