SimGurus confirmed that they are working on adding non-binary pronouns to the game in order to include gender neutral language.
Although they cannot for certain say that Pronouns will be added to The Sims 4, they did confirm that the team has been evaluating new ways of adding gender neutral language and pronoun options in the game while also having the game fully accessible for all 18 supported languages.
Question: When will pronouns be added to The Sims 4?
GrimSuruDoi: When it comes to representation, it’s not a destination. It’s a journey that we are all continuously working towards across the board. We’ve seen and read your comments regarding non-binary pronouns and their availability in game. We hear you.
At this time, we cannot confirm anything in regards to timing, but what we can say is that for a long time our team has been evaluating ways to add gender neutral language while considering how complex it would be to do so. Currently we have been investigating the changes needed, considering not only the size of the game, but the possibilities for all of our 18 supported languages to make sure that we do this work in the best way possible.