I think the issue for most editors is having too much on your plate.
Take Marvel editors-the job listing I saw-they were doing the jobs of at least 3-4 folks.
If you want better editing-they need to stick to THAT not be told to recruit, pitch books, pay attention to this and that.
Depends on the story you are doing.. Books for 12 to 45 year olds. Currently the books are 13+. Does going to 12 affect the content? Ie the legal guidelines for what they can do in the books. (Personally i think all of dcs books are entirely suitable for 11+ or even below but thats another topic)
I would say your gray area is way smaller than it should be.
Deathstroke and Terra's relationship would be more Teen Titans cartoon than the original comic.
Heroes in Crisis would probably be the version Tom King wanted.
Teen books would probably be more like the original Static comic-he's a hero but you see more of the private life and the balance of school and such.
For the most part-it's not really going to be a difference with some titles. I wouldn't really worry about it. At worst the bloodbath we have seen in some books get toned down.