Releasing a product is not just about finding an empty sales week.
Its about finding the right sales slot that has:
-the best pre-release day opportunity for marketing coverage
-the best release week
-the best post-release avoid big-scale competition week
Its hard to describe it without examples and situation, but I think it makes more example with different situations.
Imagine if Yakuza 0 was released this week.
That means that Atlus, SEGA, gaming sites, influencers, etc only have 7-9 working days to preview, stream, review and setup the pre-launch marketing cycle for Yakuza 0. Even less for those who dont immediately come out of holiday break after 1st Jan.
Ideally, you give some space to let marketing like this breathe. One week for an extensive preview, not everyone will go live at the same time. Then reviews drop next week. Then product releases a few days after that.
The best timing for the above marketing cycle of preview/review/release in the month of launch is about 2-3 weeks, and thus the best January window is around 20th or 24th of the month.
To an extent, the same logic is applicable for Gravity Rush 2. But instead of a extended 2-3 week preview/review cycle, they scrapped off a few days by just letting reviews for this game drop 10 days in advance. And while I definitely questioned this strategy at first, in hindsight it makes more sense because Gravity Rush 2 is a lower priority game for many sites, and thus some sites havent released a review or havent played enough so more reviews/impressions will drop over the next week or so.
But the Yakuza cycle is the more realistic approach for most. Finding the right slot that balanced all the marketing components is an essential as finding an empty one. An empty one that grants you lower marketing coverage may not be worth it compared to a more competitive slot that gives you maximised coverage.
As for why it doesnt instead go for February or March. Those months are worse.