This spelled out what was already understood: What was said about a policy action was almost as important as the action itself because it helped explain what the Committee was doing and set up expectations for what it might do down the road.
I think what you can glean from this little history is that the post-FOMC statement has evolved into anything but an afterthought. Rather, my colleagues and I begin thinking about our communication almost at the same time we start thinking about the policy decision itself, and we usually debate language as a way to nuance policy.