Why is a 2023 shoot unlikely or too far out? Reeves will likely start writing in 2022. A late 2023 shoot for a 2024 release sounds perfectly reasonable. Early 2024 shoot maybe.
I don’t think a sequel will come out later than summer/fall 2025. But yes, one movie at a time. Don’t leave ideas for the next movie, that’s always the best approach. That Vince Gilligan/Breaking Bad season to season approach is honestly the best process (same with Nolan’s TDK trilogy, Coppolla’s Godfather’s and Cameron’s Terminator’s). Back yourself into a corner and now you have to find a way out of it. Maybe it doesn’t work for everybody but the strongest **** comes out of that mind set IMO.
Franchises think too far ahead and the movies suffer. They should probably leave Dick Grayson and Harvey Dent out of the script.