A friend sold his HCU-affected site on September 23 to a major brand in November, according to Mark Hansen.
They re-published ALL of his content on their site in January, word for word, including his author profile.
It ranks just fine in Google with over 6,500 #1 positions or featured snippet positions.
If a site was hit by HCU and lost all of its traffic, it means that the majority of its content was unhelpful, so the site received the HCU classifier and was penalized.
If the same content is later published on a large and high-authority site, let’s say a site with 100,000 helpful pages, the 1,000 unhelpful pieces of content taken from the penalized site will not trigger the HCU classifier because the majority of the high-authority site’s content is helpful.
That’s how the same content can rank or not rank on different sites.