A badly made native app is worse than a well built react-native app. There are plenty of anti-patterns that will ruin your native app.

In stories like this its much more likely that they just got sick of refactoring a big ugly code base so got buy in to throw it all away and starting over and the justification is native. Wait like 5 years and there will be a new react-native corss platform app because the native apps have too much cruft. Assuming we still have human in the loop then.