The Audacity plug-in API is designed for plug-ins that act on the current project, or part(s) of the current project. The number and length of the “snippets” that you want to randomise, and the total length of randomised clips + silences will determine whether or not it is practical to use Audacity for the task.
If they are fairly short snippets, and the total length of randomised snippets + silences is not too long, then it is likely to be possible to create a plug-in with Nyquist.
The “.ny” files here are all Nyquist plug-ins: https://github.com/audacity/audacity/tree/master/plug-ins
Links to Nyquist documentation: Manuals and reference material