I'm actually -1 on this change -- encouraging/enabling users to use the MySQL root user or an empty password was a mistake IMO (for the same reasons as having this container opportunistically create the database -- the database user given really shouldn't have that level of privileged access 😬), and minor positive breaking changes like this are why we had this newer functionality available for users to pre-test for several months before we enabled it (and even waited for a new release of WordPress itself to do so). 😕

Additionally, for this file to even be used they'd have to be setting some WORDPRESS_... variables (otherwise we don't copy it so that the interactive wizard still works), and IMO asking them to set a few more explicitly isn't unreasonable.

I suppose one improvement we arguably should make is to update our getenv wrapper to differentiate unset environment variables from empty such that the (discouraged!!) configuration is at least possible? (#574)