My interpretation of Phil's tweet is that we will see 14 games that are currently in production from Xbox Game Studios that have yet to be released, or are receiving new content.
- The Coalition - Gears 5 (100%)
- 343 - Halo Infinite (100%)
- XGP w/Moon Studios - Ori and the Will of the Wisps (100%)
- Dlala w/Rare - Battletoads (100%)
- inXile - Wasteland 3 (100%)
- Obsidian - The Outer Worlds (100%)
- Playground - Forza Horizon 4 (100%)
- Mojang - Minecraft (95%)
- Ninja Theory - New Game Announcement (95%)
- XGP w/Relic - Age of Empires IV (90%)
- XGP w/Unknown Studio - New Game Announcement (80%)
- New Studio Acquisition - New Game Announcement (65%)
- Unknown Studio w/343 - New Game Announcement (55%)
- Playground - New Game Announcement (51%)
I consider the first 9 to be virtual locks; if 10-14 fail to show, the following games will appear in their place (ordered by likelihood to be present in the 2019 Xbox E3 Briefing):
- Splash Damage w/The Coalition - Gears Tactics
- Mojang - Minecraft Dungeons
- 343 - Halo: The Master Chief Collection
- A Different Xbox Game Studio - New Game Announcement
- Obsidian - Pillars of Eternity II: Deadfire
- inXile - The Bard's Tale IV: Barrows Deep Director's Cut
- Mediatonic w/The Coalition - Gears POP!
I'm still working out detailed predictions for the briefing and will try and post them later this week.