The fact was revealed after Sonic Origins changed the soundtrack.
Michael Jackson's involvement in Sonic has been rumored for a long time due to the game's soundtrack resembling some of the singer's songs. Yesterday, the game's creator Yuji Naka seems to have confirmed that Jackson wrote music for Sonic 3.
It all started with Naka reposting SEGA's video from TikTok, with "Billie Jean" playing in the background, and saying he was surprised the company was playing MJ's song, "Is it a sign?"
Then he apparently found out that Sonic Origins – a new compilation of Sonic remasters – has a different soundtrack from the original Sonic 3, "The music for Sonic 3 has changed, even though SEGA Official uses Michael Jackson's music."
And here it is, the official confirmation for the game's creator, but then Naka said that by "SEGA Official uses Michael Jackson's music" he meant the TikTok video posted earlier. He also felt like the translation tool he uses might cause misunderstanding, so it's not completely clear if Michael Jackson really composed music for Sonic 3 or if Naka only meant the video.
Despite the developer not confirming the fact as clearly as we would like, him talking about Sonic 3 after that video and the way he phrased his tweets seem to point to what the fans have suspected all this time. Especially considering the photo of presumably Jackson's estate Naka published just before the Sonic 3 tweet.
Whatever the case, you can't hear the music from Sonic 3 in Sonic Origins:
"While unfortunately we can't use all the original sounds from the Sega Genesis version of the game, Jun Senoue has been working really hard to adapt the original music that was composed in 1993 for Sonic Origins," said Sonic social media manager Katie Chrzanowski.