I don't care about realistic. I want to dream.
1) 343 Studios, The Coalition, Turn10, and Playground are told that they should pitch ideas for new mainline Halo FPS, Gears of War, Forza Motorsport, and Forza Horizon, but that they will all be next-gen titles. No more Halo FPS, Gears of War, Forza Motorsport, or Forza Horizon games this gen.
2) 343 Studios starts work on a new IP and Mass Effect style Halo RPG and fixes MCC.
3) The Coalition starts work on a new IP and single player story DLC for Gears of War 4 (involving Kait Diaz exclusively).
4) Purchase Playground and have them make a new open world IP.
5) Purchase Remedy. Renew the license for Alan Wake music for another 5 years. Announce Alan Wake 2 and Quantum Break single player DLC (involving Beth Wilder exclusively).
6) Wait for Spiderman to be released, then purchase Insomniac and hire them to make Song of the Deep 2, Sunset Overdrive 2, and a new IP.
7) Purchase the Ryse IP from Crytek and fund a Ryse 2.
8) Make a new studio involving Swery 65 as studio head, called "Swery 65 Studios". Make a new IP and release D4 Season 2.
9) Purchase Playdead (makers of Limbo and Inside) and have them make a new IP.
10) Purchase Thekla (makers of The Witness) and have them make a new IP.
11) Purchase Studio MDHR (makers of Cuphead). Announce Cuphead will release July 2017 and have them make a new IP.
12) Purchase Fullbright (makers of Gone Home and Tacoma). Announce Tacoma will release July 2017 and have them make a new IP.
13) For Rare: Make sure Sea of Thieves has a single player campaign that can be played offline solo.
14) Hire Playtonic to make Banjo Kazooie 3, with oversight by Rare.
15) Hire Bethesda to make Perfect Dark 3, with oversight by Rare.
16) Purchase Iron Galaxy and have them start work on a new fighting game IP.
17) Purchase Atlus. Make a Persona 5 port, a Persona 4 Golden port, and have them start working on a new JRPG IP for Xbox.
18) Purchase Platinum, uncancel Scalebound, port Nier Automata. Also, purchase the rights to Viewtiful Joe from Capcom and have Platinum make Viewitful Joe 3.
19) Cancel the indie game parity clause.
20) Add original Xbox backwards compatibility. And significantly increase the output of 360 BC games.
21) Work with Valve to make Half Life 3.
22) Purchase Silent Hills IP from Konami, then contract Kojima's new studio and Guillermo Del Toro to revive Playable Teaser / Silent Hills.
23) Hire the people who made Blue Dragon and Lost Odyssey, and have them work on Blue Dragon 2, Lost Odyssey 2, and a new JRPG IP. Have them form a new 1st-party studio called Osaka Studios.
24) Work heavily on making sure Xbox gets really important third-party games that would ideally be multiplatform. Like The Talos Principle, 999, Virtue's Last Reward, Zero Time Dilemma, Yakuzo 0, Kingdom Hearts remasters, etc...
25) Hire Armature Studios and Inafune to make Recore 2.
26) Hire CD Projekt Red to make Fable 4. Will be a massive WRPG like Witcher 3.
I can't think of anything else.