Star Trek 4 (Kelvin timeline) still has not been in development, however Paramount is now pushing for its release.
Star Trek: Section 31, featuring Michelle Yeoh as Philippa Georgiou will be released some time in 2024. It was originally planned to air as a series, but instead will be produced as a movie.
Discovery season 5 is expected to air between January and April 2024. It will be the final season.