GraphQL at it’s current state does not do anything like this. It’s basically a replacement for REST calls.
Currently i’m using Redux to take place of mergebox in my React Native app because it can’t use Meteor (yet). Also you don’t typically have multiple GraphQL queries that overlap so a mergebox isn’t really necessary.
GraphQL has a realtime spec in the works and I imagine that will have some Meteor like features in it… not enough details yet.