PHP 7 False Positives
WP Migrate DB Pro is fully compatible with PHP 7, but there is some compatibility code in our plugin that may cause false positives when running a scan for PHP 7 compatibility. These warnings can be safely ignored as WP Migrate DB Pro will still be able to function normally.
WP Engine maintains a list of plugins that cause false positives. WP Migrate DB is on this list – https://github.com/wpengine/phpcompat/wiki/Results