Business Division 3 has been working on FFXVI for 3+ years. They are a separate business division than Business Division 5, which handles FFXIV, XI, and spinoff games from the MMO universe.

In the recent past, Square-Enix reduced its total number of business divisions, consolidating 3 and 5 under Yoshi P. They're still two different offices, and two different groups of developers with entirely different product and resource allocations, but they exist under one management lead, Naoki Yoshida.

Anybody who has been following Square Enix's structural developments since April 2019 is not surprised by any of this, this is not new information and most of us have known Yoshi-P was working on FFXVI for a year and a half, just by process of elimination.