A disappointed Williams, who switched to sevens in the hope of going to the Rio Olympics, should be available for the Hong Kong tournament which starts on April 8. He posted a message on his twitter account yesterday which said: "Looking forward to getting home to my family. God willing I'm back out there come Hong Kong."
The Herald last week reported about how Williams and fellow All Black Liam Messam, back in sevens after a six-year absence, posted pictures of their economy boarding passes for the 12-hour Air New Zealand flight from Auckland to San Francisco on the way to Las Vegas.
It is World Rugby's policy to send all teams on economy class flights during the 10-round tournament.
International Players Association chief executive Rob Nichol said his organisation was talking to the global body about travel arrangements, including classes of flights, as part of their focus on player welfare.
After defeats by Kenya in their final pool match and South Africa in the quarter-final, New Zealand rallied to beat Argentina in extra-time of the plate semifinal and Japan 27-7 in the plate final.
The performances were several notches down from those in Wellington and Sydney, which New Zealand won with the help of the Ioane brothers, Akira and Rieko, Ardie Savea and Ben Lam, who have returned to Super Rugby.