How can I revert this system email being sent to my approved users. Before they need to confirm but now is it not required anymore? Or did i change something? Help I want to inform my users to login the website to confirm their account. What happened here wix?

You can change this in the Wix Dashboard. When in a Dashboard, from the navigation pane on the left, you select Customer Management. Then you click on Site Members.
From the More Actions dropdown list, you select Signup Settings.
In the dialog box, you select 'Only People who I approve manually'.
Hope it helps.