Unlikely. Scientists don't normally work this way (not to say "never"). If true it would in essence grant an exclusive right to follow a non-story. But I doubt that NPR actually has any kind of exclusive. It's more likely that only NPR is willing to publish what is in essence a background on a story, not a story per se.

For comparison, consider what happened before the Higgs announcement last summer. Because the circumstances were very different and the stakes much higher, everyone was publishing speculations about what would be announced, in advance of knowing anything at all. In that case also, there was no exclusive, but the level of publishing enthusiasm was higher.