Ok, so for the subgroup Privacy Settings, Visibility:
"Group Listed in parent group, messages viewable by parent group members"
I'm the only member of this subgroup.
However.. I now believe I was mistaken in thinking the entire membership received a notification that the subgroup was created. I have a couple of e-mail addresses in this group, only one of which is a member of the subgroup. So, when I received the email notification that the subgroup was created at both addresses, I believed that all members received it as well.
Now, I realize that both of those members are owners with all notifications checked, including "Email when someone creates or deletes a subgroup". Ugh... False alarm.
That said, I appreciate your input and I may use your suggestion to bulk change the notification settings for the members should I need to for any reason moving forward.
PS - groups.io: Unless I'm mistaken, there's no way for me to select all members at once for a mass change. I can only select 20 at a time per page of users displayed, correct?
