Global renamers are not a global group (and arguably do not need to be.) With T178842 they no longer can email users who are 'squatting' on accounts but have never made an edit.
As it stands, they will only be able to send emails from Meta. (or where the user a) has an account with edits and b) has enabled receiving emails)
Is there any way of fixing this, without needing to create a global group for the renamers?