The Star Wars New Canon Initiative is a project which rewrites the vast majority of Star Wars canon. It will involve fan-fiction stories written by various Star Wars fans. The only pre-existing thing counted as part of the New Canon is the Original Trilogy.
Only the Original Trilogy counts from the previous canon. Everything else (Sequel Trilogy, Prequel Trilogy, Clone Wars, Rebels, Old EU, New EU, KOTOR, etc.) is open to reinterpretation and reinvention. None of it is considered to be part of this New Canon, and is to be rewritten. *NOTE: None of this is done out of frustration or hatred for anything mentioned above. I love pieces of media such as the Clone Wars, the Force Awakens, certain games and books from both EUs. This is simply a way to write new and fresh Star Wars stories from an (almost) clean-slate, not having to deal with the admittedly some-what convoluted timeline of both new and old canons in the Star Wars Universe.
Things from any of the previously mentioned pieces of media can be brought over. Love Mara Jade or Grand Admiral Thrawn? Write stories involving them! Only thing is that it cannot be a copy-and-paste retelling of their stories from any previous canon. For example, do not retell the Thrawn Trilogy. Feel free to write as many stories about Thrawn as you want, but it must be new and original enough to count as part of the New Canon.
Going off the second rule: be creative! Reinvent character histories and backstories. Tell a radically different version of the Clone Wars from the one depicted in main canon. Give the Jedi and Sith new origins. Want to use Mara Jade? Maybe she had a new and different origin from what it was in the Old EU. Maybe Anakin Skywalker’s fall to the Darkside is due to pure selfishness instead of what it is in Revenge of the Sith. Be new. Be original. Be imaginative. Have fun telling new and original stories set within the Star Wars universe. The only thing that counts now is the Original Trilogy. Make it count and use it to be new, fresh and original. Invent new planets and species. Create new characters and reinvent old ones. Have fun.
Try to stay within the Science/Fantasy genre. As much as I love the Thrawn Trilogy, it was kind of the beginning of the Star Wars franchise turning into more of a Sci-Fi series and less of a Science/Fantasy-Adventure story like the Original Trilogy was. Do not be afraid to bring in Sci-Fi elements, just do not turn the entire series into a Sci-Fi story.
And that is it. I hope others will decide to join me on this project and write some fun and new stories within the Star Wars universe. Remember: Do not be too beholden to what has been done before. If it is not in the Original Trilogy, it does not count! Be creative and unique. I am currently working on some story ideas I will be getting to hopefully soon enough.