Macbook Pro (15") was updated couple of weeks ago, why this one says 263 days? Yes the retina one, isn't retina ones are successors of a previous model? Why kee

Macbook Pro (15") was updated couple of weeks ago, why this one says 263 days? Yes the retina one, isn't retina ones are successors of a previous model? Why keep them separate, I think Macbook Pro without retina will be obsolete and won't be updated.