I would imagine it would be useful in 100% of English-speaking workplaces because all workplaces have the expectation of English communication, which pronouns are essential for. If I'm writing an email or a chat message, I will typically have to use a pronoun.

Inferring pronouns has always been dumb and annoying. Many names don't have obvious pronouns, for example, the name "Taylor". Is that he or she? And clicking the little profile icon and squinting to see if someone is a man or a woman is also a waste of time. It's a lot easier for everyone if it just tells you the pronoun.