This is the type of thing that a good PR review culture will handle. I love that this is an option in some languages. But in a company, you need to decide what cool features should be used and when and how much.
With languages like Scala I think its a clearer necessity that someone or some small group in an organization maintains a dominance of expertise or you have different groups that are only using the same language in name or facing overhead to keep in agreement where a lot of the best developers might be basically doing ambassador work.