Playing devil's advocate here for a minute... since this toy has been leaked for well over a year now and we have suspiciously had no hint or mention of Cliffjumper from TakaraTomy (or any other official JP source) what if, this "Masterpiece Cliffjumper" wasn't actually done by TakaraTomy.

What if these samples were being done by one of the KO companies that have been replicating various MPs within months of their release, or a 3rd party company... by replicating all of the parts of the Bumblebee toy and swapping out a few parts. It probably wouldn't be too difficult for some of those companies that have been doing Masterpiece scaled figures with significant detailing... to strip out a Bumblebee toy and replace enough parts to replicate Cliffjumper.

I know that TakaraTomy operates to a different strategy to Hasbro (Hasbro would often do an official reveal within days or weeks of something that has leaked), but this just seems like a really long time for a toy to be floating around and not be included in a product display somewhere in Japan or Hong Kong... considering how they often display grey prototypes or odd-coloured prototypes (like MP Trailbreaker at the recent HK exhibition) just to have something out there to hype up the interest from their target market. To have these samples of Cliffjumper look to be a production level sample, it just doesn't make sense that it would already be in production (or ready to be in production) and not be listed anywhere for pre-order yet.
(I don't think we've ever had a Masterpiece toy be released straight to sale without going through a pre-order period... and pre-order periods these days for MP toys are 6-9 months now.)