Announcement day is usually related to when they plan to finish the product, and how many months they want the audience to wait/get hyped for it

You don’t know when they started working on it, how many peoples are involved, how much Sony $ are helping the development

just my theory:
maybe the SF game engines keep getting perpetually slowed down with each iteration of SF to help disguise the awful lag of the input delay netcode which also gets laggier with each iteration.

just a sinister thought.

Spoiler

just kiddin, lol