'Avatar 2' won't get Christmas 2017 release?

The much-awaited sequel to James Cameron's 2009 blockbuster "Avatar" will reportedly not be ready for its previously-planned Christmas 2017 release.
No new release date has been yet set for the movie, reported TheWrap.
The report comes just a month after the director said that the production team targeted the holiday release date. The previous release date was, however, never officially confirmed by 20th Century Fox.
The studio refused to comment on the report while individuals close to the situation confirmed it.
Some sources cited the production preparation as the main cause of the delay. Soundstage construction and some computer animation work are still in the early stages. Furthermore, a start date for filming "Avatar 2" has not been set yet.

Meanwhile, other sources speculated that the decision to delay "Avatar 2" might also be affected by Disney's announcement to move "Star Wars Episode VIII" to December 15, 2017.
Sam Worthington and Zoe Saldana will reprise their roles of Jake Sully and Neytiri respectively. Sigourney Weaver is also set to return but she will play a new character.
Cameron has indicated that the sequel to "Avatar" may be set on a moon of the planet Pandora and underwater.