I think the author was calling it "sneaky" because they haven't once publically associated themselves with these new brands. Many of the examples you've attache

I think the author was calling it "sneaky" because they haven't once publically associated themselves with these new brands. Many of the examples you've attached are products that are associated with the company, even if it's through minor press statements or warranty support. There's no page for https://en.wikipedia.org/wiki/List_of_Amazon_brands https://en.wikipedia.org/wiki/List_of_Amazon_brands :)