First of all, congratulation on the recent release of the 2.4.0 version!
I noticed that jogl-cg was not present on the 2.4.0 release, whereas it was available in v2.4.0-rc-20210111. Is this intended? I have not noticed any disclaimer of depreciation for this library. The native libjogl_cg was also removed.
There have been no issue so far to make the existing code run with 2.4.0 version combined with v2.4.0-rc-20210111 version for jogl-cg, but I noticed that this specific RC was removed from the jogamp repositories (while it is still available from other repositories).
I actually have never seen this library in JOGL distribution. Is this related to NVidia CG toolkit? What did you use it for? Maybe there is exists way to achieve the same result without CG.
Cg is no longer in active development, it's not supported on some recent graphics cards, even Nvidia advises to abandon it. GLSL and WebGPU Shading Language are more viable alternatives.