sorry but I don't have any official notification regarding date, I just read in a clipping and checked out all dates availability according to which also after 02.06.2017 extra coach was not updated in the system. So we can say that it is just my observation.
Important Note:This website NEVER solicits for Money or Donations. Please beware of anyone requesting/demanding money on behalf of IRI. Thanks. Disclaimer: This website has NO affiliation with the Government-run site of Indian Railways. This site does NOT claim 100% accuracy of fast-changing Rail Information. YOU are responsible for independently confirming the validity of information through other sources.