Computer science note: The "binary" version they're talking about is most likely compiled machine code, ready to run. If it wasn't compiled, it'd still be source code, and thus (to some degree) patchable. Once they get the file, it's just a matter of setting up servers for authentification and gameplay, then redirecting the client to the new servers. Now, setting up those servers to handle their potential load, making sure everything can talk to each other properly, and getting a copy of the i23 client to distribute to people who've lost their old ones (Personally, my old laptop is nearly dead and not up to gaming, so I'll need a new client if we get this) - that will all take time, money and effort. So I'm not suggesting that this will be particularly easy. But the offer currently on the table is a ready-to-run copy (and only the ready-to-run version) of the server code, and the capacity to license the IP so they can distribute the game client. Pretty much the minimum possible to create a functional maintenance mode, but it'll work - and the capacity for the IP to be further licensed, allowing for new media in a much-loved world, is an exciting benefit.
Also, re the licensing - did you miss the part where it would be a separate holding company? NCSoft itself would not control the decision-making about who got licenses and whether to withdraw them (though I imagine enough gore and gratuitous sex could get your license application rejected, still). It'd depend on the specifics of the spin-off, but there would be a very limited degree of control here. The licensing company would have the sole purpose of arranging suitable licenses, and games like CoT, VO and H&V are about as suitable as it gets.