While it would have been interesting to see Reeves become part of the DCU as Constantine, it is better for both the new DC Universe and Constantine 2 that the movie is an Elseworlds project. This way, the DCU can get its own comic book-accurate version of John Constantine in the future, perhaps starting with a role in the upcoming Swamp Thing before a full-fledged Justice League Dark film. On the other hand, by not being part of the DCU, Constantine 2 has a lot more creative freedom.
Not taking place in the DCU also presents an exciting challenge for the movie, as Gunn raised the bar for Constantine 2. The DC Studios co-CEO has revealed that movies developed under the Elseworlds label will need to be really good to get made, with a quality bar higher than the one used to greenlight DCU projects. Based on that, Lawrence, Reeves, and Constantine 2 scribe Akiva Goldsman will have to come up with a unique tale for the movie to make it to screens, which raises excitement for the long-awaited sequel.
Trailer video:
https://www.youtube.com/watch?v=sBU8ejvW6fM