Is the Google Nexus program dead? Has Google dumped the Nexus program? 

The Pixel is more than double the cost of the previous generation (5X /6P) - nor does it carry the "Nexus" name. 

Historically they have released a "Vanilla" phone as a tech showcase and developer friendly price-point approximately annually.
From Google Nexus wiki:


  With the expansion of the Google Pixel product line in late 2016, Google stated that they "don’t want to close a door completely, but there is no plan right now to do more Nexus devices."