I am starting a new thread on this now that many more people have decided to cancel their March trips to Italy.
Both Trenitalia and Italo are offering refunds or credit for future travel for March trips canceled due to the coronavirus. As of now, the request must be submitted by March 1. And the Italo offer appears to be limited to planned travel up through March 1. The Trenitalia offer does not appear to be so limited.
Here are the announcements ( English versions):
Note that The Web Form is only for tickets on Frecce, InterCity, and similar long distance trains, not Regional trains. And the reimbursement will be in the form of credit for future travel in the next year.
I was not able to get the form to go through without an error message until I used the Italian Web Form. So if you try in English and it fails, switch the form to Italian. After reading and using the English form, you will know what to put in each field.
In the "notes" section say the cancellation is due to Coronavirus.
And remember that March 1 will come to an end sooner in Italy than in the US.