Actually, they did not want the language to be in a videogame, not necessarily having a problem with it being heard by someone else. At least according to the article cited by Civilopedia.(the Pueblo can’t be included due to their languages. It’s considered divine and non-Pueblo shouldn’t hear it in a non-religious context, so they can’t be in Civ, which is why they were cut from Civ 5 and replaced with the Shoshone.
Here's a fairly quick YT search for a recording of Hopi with a workshop teaching the language.