Before you panic, look at the title again. He’s only SEMI-retired, not fully retired —A big difference. But the news was interesting when it came out. Masahiro Sakurai interviewed with Denfaminicogamer, and the translation noted that Sakurai views himself as semi-retired due to all the work he’s been putting into the Super Smash Bros series over the last decade or so.
He noted that between the Wii U/3DS/Switch titles, he basically worked for nine years straight. You might recall news articles about how Sakurai was suffering health issues during this development and that, at one point, he was working with an IV in his arm!
He actually talked about his “position” in the video game community with the latest video on his beloved YouTube channel. He notes that, technically, he’s an indie guy. It’s just that he’s contracted the most by Nintendo, so he works for them a lot. Masahiro Sakurai further noted that he’s the “boss of Smash Bros” and he knows that’s a very important job. Given all this, we’ll have to wait and see what he does next.