By official I mean not using stores like game stop and how good were they,what can we expect sony to offer for those willing to upgrade ps4 to ps4 4k?
Nothing. You're not doing them a favor by taking a PS4K off their hands or handing them your old console. What would Sony do with a bunch of used PS4s? GameStop has a business model built around moving used hardware and software, which is why they're a natural to offer a trade-in program.