Wait a second, how do we even know this game is coming to the west on release?. Almost None of Hatsune Miku's Games have been released to the West at the same time as Japan's release date. They usually take year's to come prior after Japan's release date, my point being Hatsune Miku is always released first in Japan then hopefully month's or year's later in the West. So with this information and SEGA having a known record for developing those game's themselves, I am confident to say that this has nothing to do with Yakuza's Development Studio's game and is probably not the game Haruki Satomi was talking about.
Also note that the teaser was mainly focused to the Japanese Fanbase with no other word from outside of the Japanese SEGA Twitter.