Bundle policy

How are sellers allowed to brand register their name and then create bundle listings of brands like Hershey chocolate, but list it under their brand. Example I register as brand “best candy” I make a listing of Hershey chocolate candy 3 bags of kisses. Then I create the listing under the brand “best candy” I’ve read Amazons bundle policy and I don’t understand how this is allowed yet there are 1,000s of these listings. If we are allowed to do this, then brand registry seems the way to go.