Originally, in an interview with wired, Myamoto stated that he was planning on retiring soon.
“Inside our office, I’ve been recently declaring, ‘I’m going to retire, I’m going to retire,’” Miyamoto said through his interpreter. “I’m not saying that I’m going to retire from game development altogether. What I mean by retiring is, retiring from my current position.”
It seems that this news got fans and shareholders scared. Nintendo's share price on the stock market fell 2% along with many fans screaming out in agony over this news.
It seems that such a backlash from a passing comment has cause Nintendo to issue a statement to refute everything that people said this meant.
It sounds to me like all that happened was that Miyamoto made a passing comment about what he's doing in the company and people made mountains out of mole hills. the way that he talks about retiring is clearly meant in a joking way and doesn't really say anything about him doing less work or leaving the company. On the contrary, he's saying how he want's to get more innovative ideas out of the younger people at Nintendo, so he's probably doing more in a sense.