@Rich35 Airbnb is not forbidding hosts from asking such questions, but the undeniable fact is that your "screening" questions are based on assumptions that are several weeks out of date, and have no benefit to you as a host. One contributor in a similar thread said it best - you as a host are not qualified to make a medical assessment based on self-reporting, and COVID-19 is very much present in even the infinitesimally small portion of the US population that has been able to get tested. It's not an "overseas" issue.
Your safest approach here is to assume that every guest and every other person you encounter - regardless of whether they show symptoms of illness, and regardless of their travel history - has been potentially exposed to the virus and might be contagious. You might even be a carrier already yourself. If your hosting circumstances are not compatible with your social distancing strategy, there's no point in pretending you can screen guests with a questionnaire; the only thing you can do is stop hosting until you feel it is safe enough again.