They haven't played every card. They'll show more megatons, as I'm sure FFXVI isn't the only thing they have. I expect a pretty strong State of Play at the end of the year to show what's coming in 2021.
On another musing note--
There's a couple of good reasons Xbox has creeped up in the polls.
Number 1: Truly, it isn't a bad system, really. It lacks games and they've had struggles, but they'll turn it around. They somehow survived Xbox One's disaster which was far worse.
Number 2: This is probably a lack of hope or frustration. What I mean that is the retailer fiasco burned a lot of people last week, so people feel very upset they didn't get remotely get a chance at a PS5, nor do they feel they'll be able to anytime soon(despite Sony's assauge). Even those that did get one may not get it on launch.
My best friend from college, I was finally able to save him by hotlinking Amazon when it went live. In the aftermath of that, he was selected by Sony.
Before those fortuitous circumstances, he was absolutely livid.
So, many may go with the Xbox, believing the order to the reservations gives them an easier ticket into next gen.