When it comes to big first party games, there's also Halo Infinity, and then there are things like Ori, Battletoads, and probably Gears Tactics and AoE4. They will announce more games - if you think that there will be no more Xbox One first party games, you're in for a surprise (of course, most will also come to Scarlett, eventually).
The X only got a pretty vague tease with some specs. I'm expecting a similar thing for Scarlett, but probably even more vague. X was not a start of a new generation, and if it was, it would probably be considered a commercial failure. They also knew that Sony would probably show off the Pro (unless you believe that they had no idea the Pro was happening - we all knew in advance), whereas Sony will not even be at E3 this time around. Blowing your load too early would just be bad marketing, unless you also intend to launch significantly ahead of the competition, which I don't believe is happening. It would give Sony all the headlines closer to the launch.
The launch line-up won't be detailed yet, but some or all the games shown will also be on Scarlett (not just through BC), and they might even show off a next gen target or two.
