Netflix is replacing Starz as the Disney home on "pay cable." Netflix cut this deal in 2012 right after they were unable to renew their partnership with Starz.
Instead of going to Starz (or HBO or Showtime) on pay cable, Disney, Star Wars, Marvel new releases will go to Netflix instead. The movie will come out in the theaters, then go to home video/PPV, and then go to Netflix when it used to go to pay cable. This starts with Captain American: Civil War; Alice Through the Looking Glass in September. Films will eventually still make it to broadcast TV and "basic cable" channels.
This is about new releases, older Disney films and series will still come and go on Netflix as they already do. This does NOT mean that all Disney movies will be available at all times on Netflix. It does not open the "Disney Vault."