I would be shocked if that turned out to be true. At best I’d expect some part of treatment very specific to COVID-19 to be free but everything else around it to be normal price. Insurance companies and hospital billing departments screw you and screw up constantly in the best of circumstances—no way I’m trusting them any more than I would a used car salesman.
Not sure why you're being downvoted because that's what they've been announcing. Whether they uphold their agreement is a different story but this what we're being told by the insurers.
Don't just call, get it in writing if you're in the USA. At the very least record that call if it's legal to do so in your state, but that's problematic for other reasons.
When the hospital decides after the fact to bill you thousands of dollars you won't have much of a recourse besides telling your family members to ignore the calls from aggressive medical collection agencies at 3am.
Call your insurer. Many are waiving testing and treatment, including for HDHPs, in respect of SARS-Covid-2.