To be honest we probably can't do quality experiments on bats either. That explains why the article describes transplanting portions of the viral coat proteins

To be honest we probably can't do quality experiments on bats either. That explains why the article describes transplanting portions of the viral coat proteins on to other viruses-- to enable growth, albeit in an artificial system. that's how things are done. The problem of limited model systems is only relevant to ebola, but many other viruses (bacteria, diseases, ....)