They're not showing any AAA game that they didn't show last year (and people already complained about that) as they can't really talk about their other big AAA titles beyond DS, TLOU and GOT, since they're most likely all for PS5, which they aren't talking about more than a year in advance.
So instead of going there and spending money and setting expectations too high for new stuff, they do this, which I'm fine with if that's the alternative and this is temporary (we'll see).
We'll still be getting nice 3rd party stuff at Microsoft's and it's not like we'd be getting, say, Horizon 2 this E3 had Sony decided to go.