First of all, Robinson Cano is not being fully represented by Jay-Z and Roc Nation, he is actually being represented by CAA, while Roc Nation handles his marketing. If Jay-Z is handling your marketing you better believe you'll be hanging out in New York a lot.
Creative Artists Agency also represents a departure from the Scott Boras line of thinking that is to get the player to free agency and take advantage of the market. CAA players actually sign extensions, and while that doesn't necessarily mean Cano will, it means it's actually a possibility now. After the Yankees made their 'extensive' offer, the two sides had no negotiations or talks. Now it might seem that contract talks could continue.
CAA has already gotten extensions for Ryan Braun (8/$45M, 5/$105M), Matt Cain (6/$127.5M), John Danks (5/$65M), Andre Ethier (5/$85M), Roy Halladay (3/$60M), Ryan Howard (5/$125M), Adam Jones (6/$85.5M), Ryan Zimmerman (5/$45M, 6/$100M), Buster Posey (9/167M) among others. Their clients who have hit free agency include Mark Buehrle, and Jason Bay and Corey Hart, Matt Garza, and Phil Hughes could join them. The precedent is there, but anything can happen. If this indeed means an extension is coming, the good news is that none of these deals were 10 years long. Braun is one of the best players in the game and he didn't even get 10 years. Posey did get nine, but his youth makes him a special case. At 30 years of age a six to eight year extension, give or take a few option years, should be the likely outcome for Cano.
Jay-Z is a Yankees fan, so he probably wants Cano to stay in New York, but that doesn't mean the team will be getting a discount. If the Yankees want him they're going to have to pay him, but this news could at least ensure that they don't have to compete with the Dodgers or any other team willing to break the bank for a game changing player and likely up the cost in the process.
Cano is going to get paid handsomely and it will be good for the Yankees to actually sign an extension with one of their players, but don't expect this to change anything in the future. The New York Yankees are a stubborn organization because they've had the luxury to be able to do whatever they want for a long time. Hal Steinbrenner will say this was a special exception, but the Yankees are really going to need to change their ways if they want to adapt to a changing market. Cano should be the first step.