They're not declaring all of the other planets non-canon. Pablo Hidalgo, who is a member of the Lucasfilm Story Group, also wrote the book that that map is appearing in - The Force Awakens Visual Dictionary. He explained that the Visual Dictionaries have historically only had a limited amount of planets on their maps, and generally only include ones that are somehow relevant to the topic of the book.That's a very small amount of canon planets in this map, its like Disney is declaring all the other planets non-canon
They're not declaring all of the other planets non-canon. Pablo Hidalgo, who is a member of the Lucasfilm Story Group, also wrote the book that that map is appearing in - The Force Awakens Visual Dictionary. He explained that the Visual Dictionaries have historically only had a limited amount of planets on their maps, and generally only include ones that are somehow relevant to the topic of the book.
The first time there was really a comprehensive map of the galaxy was in The Essential Atlas, which came out in 2009 - when the franchise was 32 years old. So having a limited map is nothing new, and the author of The Essential Atlas (Jason Fry) even said that Lucasfilm is basically keeping the galaxy as it was in Legends. So it's safe to assume that most planets are still being considered canon, even if they haven't officially been stated as canon yet.
Very depressing thoughts here...especially because of the end...Theory that's been floating around: Starkiller Base, an ice world, is located in the same spot as Ilum always was. Could the Starkiller weapon have been built on Ilum, and does its power come from all of the kyber crystals that were on Ilum?