> I'm not sure why officials haven't come out suggesting things like this. And to avoid non-mandatory travel.

Maybe because it's not needed yet? We are talking about a few cases in a country of 300+ millions inhabitants. Even if we assume that there are many unreported cases, we can still assume that the risk is extremely low.

It's notoriously hard to assess probabilities of low events, so I would simply follow recommendations from experts, and so far my government hasn't emitted any specific restrictions (besides avoiding traveling to China and a few other places).