Western Star is a wholly owned subsidiary of Daimler AG. Freightliner sells and services Western Star's at certain dealers but has no ownership of the brand. Western Star blows Freightliner away in overall quality, just like Brockway blew away Mack.
While I will not debate you over the quality if a Star, Daimler is also the parent group of both and also of Daimler Trucks North America, which you will see from this link has Freightliner, Western Star, and also Detroit and Thomas buses under "Our Brands".
While maybe my statement of Western Star being a Freightliner brand may not be correct, both are brands of Daimler so it would still make sense that if a company already has the license to use the Freightliner name, they should be able to use the Western Star name, and maybe that is a good reason the AMT Western Star was reissued after so many years.