Which is daft, because to produce a separate app specifically for debugging React Native would be a huge undertaking with zero extra benefit. Chrome's Dev Tools are best in breed (IMO) and it makes sense to leverage them.
If there were things being added to Chrome Dev Tools specifically to support React Native, that'd be different.
I think he's trying to convey that the browser is getting too bloated and that there should perhaps be a native app to handle the debugging.