Microsoft confirmed that instead of their conference being held with the others, Xbox’s show will take place in the Microsoft Theater right across from the Los Angelos Convention Center.
The Microsoft Theater will be hosting Xbox’s E3 2018 Briefing, on June 10th, at 1PM PT. It will also include Xbox FanFest activities, hands-on gameplay and demos for all E3 attendees and more. The theater give Microsoft the ability to interact with more fans and partners than ever seen before at an Xbox E3 conference.
Microsoft also stated they will still have a presence at the official E3 floor, saying there will be a booth completely dedicated to Mixer, so people can stream and interact with games. This is set to be the “biggest E3 show ever” for Microsoft.
Source: Microsoft