https://www.youtube.com/watch?v=x05U75X3_Wg
It seemingly sets the stage for some sort of rampart mutant genocide, we suspect the legacy virus might be playing a role. The legacy virus was a fictional plague within the mutant community killing massive amounts of them.
There is also a hint to Logan’s possible murdering of the X-Men as he did in Old Man Logan with this shot here.
The trailer footage also confirms that actress Dafne Keen is indeed playing Laura aka X-23 in the film.
SOURCE: FOX