6.0 update strangely disrupts dreamhost mysql server?

5/24 pm: updated all nine site on one dreamhost account to 6.0, everything seems fine with 6.0

5/25:
7am EDT: One of nine sites cannot establish database connection https://k9tack.com

8am: Zero of nine sites can login to wp-admin. All nine sites are up. There’s no explicit error when wp-admin login is attempted. When incorrect password is submitted, the usual error is returned.

8:05am: https://panel.dreamhost.com/index.cgi?tree=advanced.mysql reports: “NO hostnames exist for these databases… They are INACCESSIBLE until you add one!”

8:10am: Dreamhost support reports they’re having a problem to manually re-add the mysql hostnames. The server team reports: ” When we try to add a hostnname, the server responds with ‘hostname already exists’ ” Support continues with: “rest assured we’re working to re-add all your hostnames”

What do you think? Are they really trying to tell us a “possibly” missing database server hostname can take down the wp-admin, and not the site itself?

It looks like there’s some dreamhost code in the wp-config.php:

/**
 * Removing this could cause issues with your experience in the DreamHost panel
 */

if (preg_match("/^(.*)\.dream\.website$/", $_SERVER['HTTP_HOST'])) {
        $proto = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? "https" : "http";
        define('WP_SITEURL', $proto . '://' . $_SERVER['HTTP_HOST']);
        define('WP_HOME',    $proto . '://' . $_SERVER['HTTP_HOST']);
        define('JETPACK_STAGING_MODE', true);
}