The Tangled Before Ever After teaser was uploaded 5 months before the release date, and we don’t currently have an exact release date for the Big Hero 6 TV
series, but presumably we’ll get our first teaser 5-6 months before it.
All we know is that the Big Hero 6 TV series releases this fall, so that’s in like September, October or November.
And using the logic from the Tangled Before Ever After teaser, we should get a Big Hero 6 TV series teaser in April, May or June.
Maybe if we’re lucky we’ll even get one in March. But…I really don’t know. I’m just speculating here.