Since the Micromasters were released 2 years after Scorponok, it is possible that Hasbro were planning a redeco like Takara did (Black Zarak a year after Zarak/Scorponok).
Or maybe, the plan was to have Metroplex and Scorponok redecoed and released with the Micromasters as base-formers, but Hasbro later canned the idea, while Takara still went ahead and redecoed Metroplex as Metrotitan.
The colours made me think of Sixknight though, the JP redeco of Quickswitch.