I think that pop punk as a musical genre is a major revenue generator for major music labels. Pop punk is, and always has been, popular with the younger crowd. They usually grow out of that kind of music but it is always nostalgic and there is always a younger generation to take their place.
Pop punk is a legitimate revenue generator for major labels. Pop punk is popular enough that it is a fairly safe place to invest money for promotion and still funky and odd enough to be view as cool enough to bring in some new fans. The artists are usually capable of bringing some controversy to the genre and controversy brings free exposure on many news outlets.
All music serves as a major revenue generator for major labels. If they find they can make good money off the new hit music such as pop punk they are going to take advantage of it. Today it is pop punk tomorrow though it will be a different music genre.
Pop punk is not a major revenue generator for the major labels. Pop punk is not mainstream enough in order for it to become a major revenue generator for the major labels. So no, there is no way that pop punk is a major revenue generator for the major labels.
No, pop punk is not a major revenue generator for major labels, because it is not what people want to listen to. No matter what other niche genres spring up to complain for our attention, ultimately, people still just want to listen to basic pop music. If it's not what the people want, it will ultimately not generate much revenue for the major labels.