The things is the majority there just dont speak English and every forum/site/blog or whatever they dont even bother translating it. I had many cases where I wanted to see something it's on BR site and it has no English, it's just (Portuguese?)
They are a large community in mugen, but I wouldnt say in Blizzard's. Although, can tell you why each of these countries has been chosen based on their activity in esports. but since this is a mapmaking contest I dont know how they determine that since it's not like you see news like 'X made a map on Monday, it was the best map ever created, next big tournament is between Germany and Russia. Mapmakers will compete to create the best map for the shortest time'. No such things in mapmaking, so I've no idea, must be having business with those countries.