Considering how much space and empty time there is to play with in the Star Wars universe, the only way the EU would even be effected is if episodes VII-IX directly contradict what happens there. If they simply choose to tell a story from the EU, or better yet, create a new story that doesn't contradict the EU, then nothing changes. I don't see why people are making baseless assumptions about the status of the canon when we don't even know anything about the story yet. There's a very real possibility that Disney will choose to cover some EU event (like fighting the warlords post ROTJ, or the formation of the New Republic) from a perspective we've never seen before, therefore making an "original" story.
Sure this is true, but it can't help but having an effect on the EU, it will create 'ripples' if you like which will affect exisiting EU in some way or another, but I agree - sending a bulldozer through the EU is avoidable, but it is difficult.