Obryn
Hero
...because it's an advertising blurb. For their newer products done by the marketing department.It's a statement by the publisher under the section: Intended to be used with the following products. As such the statement serves informational purposes.
You're free to make of that statement what you want.
Personally, if WotC wanted to communicate that the product is primarily intended for Heroes of... buyers, and secondarily at PHB clients, they could have made the items in that list a wee bit longer. But they chose not to.
I mean, are you arguing that because some marketing goon didn't list the PHB, the designers didn't intend a PHB Wizard to take any Heroes of Shadow powers?
-O