Sounds about right to me.
I personally don't think any of the Xbox conferences this generation has been the 'best', bar the surprise backwards compatibility announcement.
For this Marcus chap to say that their E3 conference may well be "the most interesting" in light of Microsoft's new-ish direction with Game Pass and the like, I don't doubt he is wrong.
I do not 'follow him', or anybody else for that matter, but wasn't he 100% right in all of the Nintendo Direct bobbins and Crash Banidicoot related news this past week?
I'm really tempering my expectations this year after being sucked into the ridiculous hype of their E3 show last year, and ended up profoundly disappointed... apart from the very welcome revealing of Ori and the Will of the Wisps!