Hi @didoemilio,
You are correct that the “Review_Complete” email template was removed in recent versions and replaced with an automated notification to the editor. This notification should be received by editors and will say "A reviewer has commented on “Article Title.” Since this is a notification and not an email template, the text cannot be customized.
There was an issue with an earlier version (3.1.0.1) where this notification did not come through for journals using custom review forms, but this was addressed in later versions.
I tested this on version 3.3.0.8 and the “reviewer has commented” notification was received by the editor with and without a custom review form being used. Can you confirm that none of your editors are receiving this notification? Do they receive other automatic notifications, such as the one that’s sent when a reviewer accepts or declines a review request?