In addition, the way the other characters talk about Donna (Streep's role) in the trailer strongly suggests that she has been killed off from the original. Many of us have been speculating in the past couple months about the extent to which Meryl is even in this movie, and now it seems that what role she has may be incredibly small. This is too bad, as most promotional coverage or news articles that have come out tend to lead with the fact that she's participating, suggesting a much larger role than we apparently now know she has.
I'm not as devastated as most of the Twitter posters I've read so far, as my initial awareness of Meryl signing on for this in May sort or irritated me. But with the incredible box office success of the 2008 original, it seemed reasonable that she'd join, if not just for a cameo.
It'll be interesting to see when the trailer is officially released and we get more clarity on this topic. But as it stands now, it looks like Meryl will have very little in the works for actual screen time in 2018, expecting her role in Mary Poppins Returns to be quite small as well.