There seems to be a lot of buzz on the interwebs today about the possibility of getting a trailer for Episode IX sometime this month and it got me thinking about the production timelines of the other two sequel films and when their announcements were made.
Episode VII began filming 14 May 2014. The film wrapped shooting in September. On 6 November 2014, the title of Episode VII is announced to be The Force Awakens. Post production on the film was completed sometime in August of 2015. The first trailer for the film debuted 28 November 2014. Tickets went on sale 19 October 2015 and The Force Awakens opened in theaters on 18 December 2018.
Episode VIII began shooting 15 February 2016 and completed filming in July. The title of Episode VIII was announced as The Last Jedi on 23 January 2017; debate on whether or not ‘Jedi’ is singular or plural ensues. The first railer for The Last Jedi was shown on 14 April 2017 at Star Wars Celebration Orlando (and I was in the room, still cannot believe), at the end of the panel about the film; the panel and trailer were also streamed live online. The Last Jedi wrapped post production in September 2017. Tickets went on sale 9 October 2017 and The Last Jedi was released in theaters on 15 December 2017.
Production on Episode IX has not yet wrapped; it began filming on 1 August and I believe it is supposed to complete in February. It is highly unlikely that Disney will release a trailer before the film is completed. Moreover, we just got a second Captain Marvel trailer and are expecting the first Avengers 4 trailer / title announcement pretty much imminently; apparently its release was delayed until this coming Friday morning.
All of this to say: I think we should expect a title announcement in mid-late January or the beginning of February, and I firmly believe that the first trailer will be released at Star Wars Celebration Chicago, much like the trailer for The Last Jedi. (No, I’m not just saying that because, again, I’m going to be there.) Episode IX will be released 20 December 2019.