Shigeru Miyamoto says that Nintendo will have to be more proactive in creating new characters, but has to be careful about it.
One thing Nintendo has continuously gotten stick for over the last decade or so is the tendency to rely on legacy series for its games. And while there have been more attempts at bringing something new to the table than many give it credit for (remember Codename S.T.E.A.M.?), a new IP – especially before 2015 or so – was a bit of a rare sight for Nintendo. However, Splatoon has proven that the sauce is still there, and has gone on to be one of Nintendo's premier franchises in its 11-year lifespan.