I honestly don't see it, though anything is obviously possible. I just don't think the Reds will rush Leake to the majors, especially when they have other options with much more professional experience (e.g. Matt Maloney).
With Chapman, there is definitely a sense of urgency to get him to the majors. The Reds handed out a large contract and with all the hype he is generating, fans will want to see him sooner than later. On ESPN, one Reds source told one of the talking heads that the Reds are inclined to push Chapman to the majors to get more fans in the seats, especially after all these losing seasons. Although Leake is an excellent prospect, there's nowhere near the hype or urgency with him as there is with Chapman. Even if Leake blows everyone away in spring training, I still see him spending at least a couple months in the minors.