Recently, multiple pieces of music have been added to the database under the name of Kenji Yamamoto.
"OMINOUS SILENCE" is a track from Kai and this had been his last work in the database for a decade. "YAMAMOTO KENJI" is apparently a musician who shares the same name and it's not the Yamamoto we know, so the three tracks created by this person are not related. All the other ones below the first four have been registered in 2021 considering their serial numbers, and 山本 健司 is credited for them just like the Kai score.
The detailed information of these pieces credits Yamamoto for "musical composition," so he's not just an arranger here. After the scandal, he did music arrangement for some songs under the name of "Kenz," but he hadn't composed anything since then, so this is his first activity as a music composer in the last decade. The distributor is "Music Airport," which is a music label founded by Matsutake Hideki, Yamamoto's old and close friend.
Matsutake is a synthesizer musician who is most known for working under Yellow Magic Orchestra. He has been a friend of Yamamoto for decades and they once worked together for the soundtrack CD of Super Budtouden. There was his interview on Yamamoto's now defunct website, and their bond seems very tight.
Considering all the information I gathered, it is safe to say that Yamamoto is now back as a music composer after a decade of hiatus, with the help of his old friend. However, this obviously does NOT mean that he makes a comeback to the Dragon Ball franchise and his old works are going to be revived, but it is good to know that he is making a step forward and restarting his career.
