I was super excited when I started reading this article, I thought they were talking about a direct measurement of the CNB.
Right now, the CMB is as far back as we can see in time. That radiation originates from a time when the Universe was around 380,000 years old. The CNB originates from when the Universe was two seconds old. A direct measurement of it would be an astounding achievement and would give us many new insights into how the Universe formed.