If you read the article about "Mary Poppins 3" it says they are tossing ideas around and how it depends on how "Mary Poppins Returns" does. It is not doing the kind of business to warrant a sequel when it comes with a $130million price tag.
Saw this when I was very young and loved it. Made my mother take me twice! I bugged my parents nonstop for weeks to take me and they finally gave in. First album I bought with my own money. $4.00! I couldn't afford the extra dollar for the stereo version. I have high hopes for the sequel...
And just to add to what I said above, when I saw Christopher Robin they showed the same teaser trailer, which is kind of dark and ominous looking. However, they showed a trailer for Dumbo that included large segments of the film. Maybe they think mystery is best? Disney tends to know what...
I agree with Jake. Saw Christopher Robin yesterday and expected a trailer that showed a bit more. It certainly wasn't going to do anything to grab those who are unfamiliar with it - especially the kids in the audience.