What if you deactivate this plugin? Can you still log in some how?

Sometimes when you’re having problems with your site, it’s nice to be able to temporarily deactivate all your plugins to make sure none of them are causing the problem. But, I’m not sure what would happen if I deactivated this plugin. Would I be able to log back in? Would it revert back to the old default wp-admin login or what?

https://wordpress.org/plugins/rename-wp-login/