I just installed Matlab 2023b and configured it with the latest PsychToolbox 3.0.19 (2024-01).
The previous versions are still available: Matlab 2022b configured with PsychToolbox 3.0.14 (2019).
For ongoing studies with PsychToolbox tasks, you may wish to either keep using the old version, or test your tasks on the new version and switch.
To avoid potential problems, I changed the Matlab color settings so that version 2023b has a “dark theme”, while 2022b has the default “light” colors. So it should be very obvious if you open the other version by mistake.