Selectional restrictions refers to semantic restrictions that are imposed on the environment where it occurs by a word. Thematic restrictions are restrictions related to themes.
On the other hand, collocational restriction refers to the linguistic term that is being used in morphology. The restrictions are associated with the culture of a language.
I feel as if it is cultural context as it might be okay to talk about those kind of things in the United States but it is not acceptable in Saudi Arabia as the culture is very conservative compared to the U.S.
