It's been speculated that what you're seeing in the trailer is a reverse. The beginning of the trailer is the end of the prologue. The end of the trailer is the beginning of the prologue. The reason this has been suggested is that in the game poster, Lucia is wearing an electronic tag around her ankle, whereas, at the end of the trailer she doesn't. There seems to be an opinion that the first scene of the trailer with Lucia is prior to being let out on parole (hence the electronic tag), and the game takes place from there.
There's also some speculation that just like in RDR2, if people see a crime they'll report it, however, because GTA VI is social media themed, there's a chance that bystanders will take videos of you doing things like robbing places or beating someone up and it going on social media and that playing into the idea of 'notoriety'. Could also tie in with the parole prologue ending where you have to be on your 'best behaviour'.
Obviously speculation right now, though.