Reggie Fils-Aimé's recent lecture at Cornell University delivered many tasty and amusing pieces of information, including the fact that the late Nintendo present Satoru Iwata didn't want to bundle Wii Sports with the Wii, and that Reggie himself considers the Wii U to be a "failure forward".
Mother 3 is, of course, the direct sequel to EarthBound (Mother 2 in Japan) a game very dear to a large number of Nintendo fans. Released on the Game Boy Advance in 2006, it has never been officially localised for western release – although an excellent fan-made translation does exist. In 2016, there were rumours that a release was happening, but it has been suggested that the project has been put on the back burner due to the game's "controversial" elements.
Suffice to say, the topic of Mother 3 came up several times during Reggie's tenure at Nintendo, and it only stands to reason that he would be asked about it again during his Cornell University talk. You can watch his reaction below.
Nintendo has, in the past, poked fun at the demand for Mother 3. During the company's E3 digital event in 2014, a stop-frame animation segment created by the team at Robot Chicken sees Reggie hurling a fireball at a fan who asks for the game to be released in the west.