In a tweet, Konami said additional maps and Survival mode, which was featured in previous versions of the game, are coming to MGS V sometime later down the road. More details will be announced later regarding all of this content.
In addition, Konami has pushed out a new MGO update, 1.02, that makes it easier to level up (required amount of XP has been reduced for each level) and changes weapon values. In particular, the update increases the lethal shotgun' knockback range. On top of that, draw speed has been reduced for machine guns and the SERVAL AMR-7 gun. Adjustments were also made to MGO's Stun Grenade.
"In version 1.01, even if you are not facing the point of the explosion you can find yourself temporarily blinded due to the flash, however in Ver. 1.02 as long as you are facing away from the explosion, you will not be affected," Konami said.You can see the full MGO 1.02 patch notes here.