I'm already sold on Scorpio and State of Decay 2 is a guaranteed pre-order. I want to see a blowout of Crackdown 3 to see if it's for me. Showing me Halo 6 does nothing for me as I have no interest in that franchise. I enjoyed Gears of War 4 and im looking forward to GOW5 but at the same time, I know that it's coming and I don't need to see it until the year it comes out.
The reason why Microsoft's IP's don't sell outside of the big three is because they don't showcase them correctly or they're overshadowed by other games. Halo 6 especially ending the conference WILL BE the main conversation of the show, not Crackdown 3 or State of Decay 2 and then when both those games fail to meet sales expectations, Spencer and others will wonder why.
It's because they don't give them the love and focus that their big three get. Can't expect other IP's to sell when you're treating them like crap compared to the big three. Microsoft has to go all out with Sea of Thieves, State of Decay 2 and Crackdown 3 if they want them to succeed. Forza Motorosport 7 will sell it's normal few million copies and doesn't really need a lot of stage time.
Add in Scorpio reveal of what it looks like, the price/release date, Ori 2 most likely being announced, ACO and Shadow of War along with short segments for AR/VR, the new interface, Game Pass, etc. and they have a good show.
If Sea of Thieves slips to after E3 2018, they can also show that off again next year along with Halo 6, Forza Horizon 4 and hopefully, Playground Games new IP. Microsoft can easily have a foundation for this year and next year's E3 shows that they can build around on.
Also, with all the talk always being about how Microsoft has nothing but the big three, ignoring Halo and Gears this year would prove otherwise to those who believe that. If all they do is end E3 with Halo, it's simply the same shit, different year.