That trailer really reminds me of the movie, "Gray State" which was supposedly completed several years ago (2015) but before it was released, the director (David Crowley) and his family (including young children) were found dead. The media claimed it was a murder/suicide with him pegged as the murderer. The movie disappeared and was never released.
Interesting, you can no longer find the trailer on youtube where I saw it years ago, but a shorter version is on tic-tok.
Trailer for the movie, Gray State