Thanks a lot @rodlie!
I updated the Wikipedia page to point here.
edit For the record, I think that MrKepzie’s assertion that “loading Python scripts in a GPL software does not make them GPL” is wrong as soon as the Python scripts imports Natron’s module. Similarily, it has been established that Blender’s python add-ons must be GPL because they do import bpy and the bpy module (Blender’s) is GPL.