Timothy Carney lays it out: the idea was to increase the number of Congressional seats to 437 and trade creating a full Congressional seat for DC (effectively guaranteed Democratic) for an extra one for Utah (effectively guaranteed Republican, and Utah was next in line to get an extra seat because of the 2000 census). The deal never came together, but it was definitely an offer. Only now, because of the Census, Utah gets an extra seat anyway and the state that would next in line for an extra seat would be North Carolina.
North Carolina’s Congressional map is enough of a disaster area as it is already: the last thing that the legislature needs is more complications while it tries to fix the gerrymandering caused by a century of Democratic malfeasance. No deal.