When will my Mac (13inch MacBook Pro Mid 2013) become a un serviceable product in California?
Residents of California can obtain service and or parts for up to 7 years under the Song Beverly Consumer Warranty Act.

First, what Apple terms "vintage" and "obsolete" are not in anyway bound legally to what California law provides for.  For the record, Song-Beverly provides for manufacturers making parts available for up to 7 years; Apple can, in it's discretion, make "Vintage" in 8 years.

Secondly, the law only allows for replacement parts and service information be made available. 


  Every  manufacturer making an express warranty with respect to an
  electronic or  appliance product described in subdivision (h), (i),
  (j), or (k) of Section 9801 of the  Business and Professions Code,
  with a wholesale price to the retailer of one hundred  dollars ($ 100)
  or more, shall make available to service and repair facilities
  sufficient  service literature and functional parts to effect the
  repair of a product for at least seven  years after the date a product
  model or type was manufactured, regardless of whether the seven
  - year period exceeds the warranty period for the product


To put this in layman's terms, see:  Sold a defective electronic device? California Law Protects You


  To be clear, the law does not force manufacturers to replace an
  electronic device that no longer works. Instead, the law requires
  expressly warranted electronic goods to have replacement parts
  available to consumers and service information available that allows
  enough information for repairs.


What's most important here, is the context of that warranty point you brought up:


  Products purchased in the state of California, United States, as
  required by statute.
  
  
  Owners of vintage Mac products may obtain service and parts from Apple service providers within the state of California, United States.
  


(emphasis mine)

TL;DR

The Song Beverly Consumer Warranty Act says that the manufacturer (Apple) must make available parts and service information for up to 7 years on your electronic device (MacBook) that was purchased in the state of California.  This doesn't extend the warranty to 7 years.