Re: Would the Legacy costume work on-screen?
No, there's nothing that happens in The Wolverine that would have required the suit. It wouldn't have made sense at all.
That suit in the photo is from a 3D printer, so I don't think it was a suit meant to be tried on. Even if it was, can you imagine if they released a photo of him wearing it and then not have it the movie? The fans would have a fit.
I'm getting a sense that we'll see some form of it in DOFP, though. It would nicely bookend the, "What would you prefer, yellow spandex?" line in the original film to see a version of it in one of these timelines.
"You change the world when you change your mind.