Update: The teaser has been released, which is for Marvel's Agents of SHIELD Slingshot.
Marvel is planning on releasing a surprise teaser following tomorrow night's winter season mid-season finale of Agents of SHIELD.
Actress Natalia Cordova, who plays Elena 'Yo-Yo' Rodriguez on Agents of SHIELD, tweeted out to Chloe Bennett (Quake) that she loved working with her and said to make sure to watch the surprise teaser Marvel has after the finale.
It's unknown what the Marvel teaser could be for, but it's possible the teaser could either be for the return of Agents of SHIELD following its winter break, perhaps a new Ghost Rider spinoff series, or the teaser could even be related to the new Inhumans IMAX event TV series.
Regarding Inhumans, it has said not be a a spinoff of Agents Of SHIELD, so the teaser may have nothing to do with it, but Marvel TV and IMAX are developing an Inhumans TV series which will debut with the first two episodes in IMAX theaters. You can expect a lot of promotion for Inhumans, so maybe it kicks off tomorrow night.
Update: The teaser is not for Spider-Man: Homecoming, and probably not for Inhumans or Ghost Rider.
Absolutely love working w/ my girl @ChloeBennet4!
Make sure to watch the surprise teaser @marvel has after the finale.#AgentsofSHIELD https://t.co/C54Gd32gww
— Natalia Cordova (@YOSOYCORDOVA) December 5, 2016