Hi @aleksandreeu, thanks for the report, and good catch again. You found the same kind of hole as the password reset one: the plugin was switching the notification off through the WordPress filter, but some registration and membership plugins ship their own copy of the function that sends this email, and that copy ignores the filter entirely.
Version 2.7.5 now intercepts the “New User Registration” email right before it is sent, whichever plugin builds it, so the switch holds everywhere.
Could you update and confirm it is gone on your site?
