Although Titans exists on its own Earth, separate from the Earth that The Batman exists on and other big screen adaptations, such as Joker, Brenton Thwaites is hopeful that there may be an opportunity for his version of Nightwing to join the DCU, the Earth that holds all the DC characters on the big screen. However, whether this is in the cards for the actor is determined by how Gunn chooses to move forward with the franchise.
Chris McKay, the director of The Lego Batman Movie, was signed on to write and direct a solo Nightwing film in 2017 before WB put the movie on hold. Since then, there have been fan casts, such as Dylan O’Brien as Nightwing, and cosplay showing how the character could work in live-action. Despite Nightwing not coming to fruition on the big screen, Thwaites brings him to life in Titans.
During an interview with SFX, Thwaites was asked if he would be open to doing a Nightwing film set in the DCU. Thwaites responded by saying that not only has he thought about those possibilities but that he would love to do it. However, the actor admits that the decision is ultimately up to Gunn and his 10-year DC Studios plan. Thwaites expanded on this by expressing the great honor it would be to bring Nightwing to the big screen and that with the correct budget, it has the potential to be a great superhero film.
There haven’t been any updates regarding the previous Nightwing film and whether it is part of the franchise's future or if it will join the canceled Wonder Woman 3. Even so, Thwaites as Nightwing is the right age relative to Ben Affleck's Batman, and fans have already come to appreciate Thwaites' take on the character, especially as the first live-action Nightwing. However, Zack Snyder stated that the Robin who died in the DCEU was Dick Grayson, teased in Batman v Superman, although there is nothing to signify this, so those plans could be subject to change.
This is not unlike fans wanting Grant Gustin's Flash to replace Ezra Miller, but as previously mentioned, those series counterparts exist on a separate Earth within the context of the DC Universe. The plans for replacing actors, or bringing an already established version of a character to a different series or set of films, such as from Titans to the DCU, would involve a full-on reboot or a crisis-level Justice League event that connects different Earths, as was done in Spider-Man: No Way Home or the upcoming The Flash. Also, bringing an already established character from one Earth to another may signify the death or reset of the previous series, which could work depending on how Warner Bros. Discovery wants to move forward.
Titans season 4 is available on HBO Max.
Source: SFX (via Comic Book Resources)