We were hoping to hear some details as to why Hiromichi Tanaka was suddenly departing Square-Enix, but now that we have the details, I wish the explanation was a bit happier. Tanaka has said that he has a major illness and is leaving the company due to health issues.
It sounds like Tanaka is hoping to best these health problems, as he also cited his interest in returning to game development as a single creator.
Hopefully Tanaka is able to surpass his illness and return to the work he loves. We'll keep good thoughts about him in our minds and hope that all turns out well.