Why do I not have gopro lens distortion effect preset

GoPro presets are not missing; they have been removed from the program, as they were for very old models.

You can make your own set of presets.

I have the same problem.  I used to have them several versions back but now they are no longer there.  Did Adobe remove them?

If Gopro lens distortion presets are missing just use the 'Lens Distortion' effect in the 'Effects' menu and manually adjust it so it looks right - start by adjusting 'curvature' to a negative value and adjust by 'eye'. Once you have it the way you want don't forget you can now save this setting as a preset for future use.