No. That's what the instance block will do when we get it. Right now with the domain block, the point of it is for example, say you hate imgur.com. Why? Doesn't matter, you just do. You can block the imgur domain so nothing from imgur, regardless of where it's posted, will appear in your feed on kbin. If I post a picture linked from imgur on m/gaming, you won't see it when you browse that magazine.
If you try to block an instance with that same method, posts and comments still come through fine. I've blocked a bunch of European instances due to language issues but the posts still sometimes comes through regardless (and many other people have commented saying the same over the last month, hence why we'll be getting a proper instance block soonish).