Since it's a partner showcase I would like to see more of Final Fantasy 7 Intergrade and Elden Ring in action. Framerates/resolution/stuff like that.
A preview of Duskblood would be cool too, since it's a high profile exclusive.
Resident Evil Requiem would be awesome. And when you're at it, announce the whole slate of recent entries and remakes of RE.
Newer stuff like Silent Hill F and Silent Hill 2 wouldn't be too bad either. Or stuff like Hell is Us, Cronos or Wu Chang: Fallen Feathers.
I expect a lot of stuff from Microsoft. They supported the Switch pretty well and I bet they are eager to show some love for the Switch 2 as well.
An Announcement from SIE would be funny too, if only for the meltdowns it would bring.