The Takumi-san Ishii is referring to may be Shu Takumi, the creator of the Ace Attorney games. In Japan the Ace Attorney games are called Gyakuten (reversal or turnabout) series. Ace Attorney: Phoenix Wright is called Gyakuten Saiban while the Ace Attorney Investigation games are Gyakuten Kenji.
Since the “○○” is in the title it’s unclear if this will be a new courtroom drama game or a spin-off. A little bit before Tokyo Game Show, Capcom announced Ace Attorney Investigations 2.
Update: Jiro Ishii posted a followup tweet saying there was a “misunderstanding” about the Gyakuten ○○ tweet. Time Travelers is the only game Ishii is working on. Thanks for the update SupaPhly!