However, in an interview to celebrate Sega's 60th anniversary, he admitted that he hasn't. But if he ever got the chance, he'd do things differently:
"In the sense that I want to try it… well, Sonic. After all, when you hear SEGA you think Sonic. I'd like to get involved once at least. But for me, the so-called Sonic is, well, if I were to do it, I wouldn't do Sonic as it was. I would like to make a completely different Sonic."
Considering how Sonic has been doing in recent years, a "completely new" Sonic actually sounds like a pretty appealing pitch. But whatever new Sonic game Sega is working on, clearly Sato isn't involved. He wouldn't have talked about it if he was.
So we can only hope that whoever is currently working on Sonic has the same idea.