So after watching the trailer a few times, I noticed a few things.
The Dorothy that is shown is Dorothy V, and it's pretty beat up. In the original, they only made 4. This leads me to believe that Daisy Edgar-Jones' character is in fact Bill and Jo's daughter, and she's continuing their project. They're saying this isn't a direct sequel, but I'm not buying it now.
The siren sound effect is the same from the drive-in scene.
In the original, they used slowed down animal sounds for the tornadoes, and I noticed they used a slowed down cow moo in the trailer.