We know Peter Mayhew is in, and that is a very good, dare I say, screen-ready Chewbacca… Though it was Alan Horn, not Bob Iger, that we know for sure would be in London around this time. But if this was a (new?) theme park Chewie, wouldn’t they have someone in it? And why would they post it on the official Star Wars Instagram instead of a Parks one? So yes, it’s not too much of a stretch to believe this is the Episode VII Chewbacca costume!
Noteworthy: StarWars.com’s Matt Martin says “The image was supplied to is without much context. No idea where/when it was taken.” And the official (well, verified) @StarWarsUK account says it is from Episode VII, but Matt says it was only speculation on their part. Curious.