In the second trailer for Starring Robert Pattinson as the titular Dark Knight and directed by Matt Reeves, The Batman will see Bruce Wayne in his second year as the Caped Crusader. Still a young man who has yet to refine or fully control his rage, the new trailer features a voiceover from Wayne talking about the Bat-Signal itself, giving it a darker connotation and meaning in contrast to the hope it inspires later on in Batman's tenure as Gotham's protector.
As revealed in the second trailer for The Batman released during DC's FanDome 2021, the new footage shows just how brutal Pattinson's Batman will be. Furthermore, it appears as though this early Wayne is much more focused on delivering vengeance as opposed to justice. This concept is not only proven by the Dark Knight's brutality facing a gang of clowns, but also in a voiceover where Bruce Wayne references the point of the Bat-Signal as the GD's Jim Gordon turns the iconic light on.
According to Pattinson's Dark Knight in the Batman who've been in the vigilante/superhero business for longer than Pattinson's.
It appears as though Bruce Wayne's evolution and growth into a hero has yet to come in The Batman, which is ultimately a good thing. Seeing him operating solely as a vengeful vigilante is a new kind of Batman on the big screen that should be very entertaining: a Batman unburdened by origins while not being fully developed either. As a result, it makes sense that the symbolism of the Bat-Signal would also not be fully realized (yet).
In any case, seeing such an iconic light in Gotham being viewed in such as dark manner is very dynamic. The change in meaning for the Bat-Signal is quite telling for the film's overall tone as well, featuring Robert Pattinson's grounded and gritty Batman determined to make his enemies fear him and going to extremely brutal lengths to do so. While Bruce Wayne has always been shrouded in darkness as Batman, framing the light of the Bat-Signal as an equally dark part of his arsenal will be pretty significant when The Batman releases in March of 2022.