This Costa Mesa thing is about more than just not wanting patients at the local hospital. If you read the court filings the patients would not be going to a hospital AT ALL. The propose plan would be to house them in an abandoned residential facility for people with disabilities which is described as being dilipidated and requiring renovation before it is habitable. Also, the filing describe that this plan was made between California State officials and Fed officials, and when emergency reponders shared their concerns with the city officials, they were reprimanded.
https://www.ocregister.com/2020/02/21/costa-mesa-asks-court-to-stop-relocation-of-patients-diagnosed-with-coronavirus-to-fairview-development-center/