Following Heroes of the Storm's ladder revamp, StarCraft II: Legacy of the Void will get its ladder improved as well. It is a funny coincidence that Blizzard is revamping StarCraft's ladder right after Heroes'. Basically, the Heroes of the Storm ladder system is based on the one that players have in StarCraft. You have all those Diamond and Grandmaster rankings there as well as promotion demotion matches and so on. The developers decided to improve the ladder even more. Soon, StarCraft's ladder is going to be better. The system will show your current Matchmaking Rating and will be more transparent.
Watch this developer blog and get the idea of the upcoming changes: