A more rational organisation makes sense, but as others said, top tier should offer more than what has been leaked.
Anyhow, a single service platform with different levels makes the gamers life simpler and allows to make them nicer offers, for example users could receive some free weeks of higher level services after they bought a given amount of products and/or services, this is just one of the things that become easier if the service platform is unified.
Then there is a big benefit for Sony, marketing costs drop and their effectiveness rises. This can be more beneficial than the savings on services operating costs.