It only applies to the All Site Stories folder. Right now, I am going to expand it to three options:
-
Folders only
-
Folders and feeds
-
No confirmation at all, which is going to be the default in your case
If you want to hide the button entirely, you can do that with custom CSS. (Manage > Account > Custom CSS):
.NB-feedbar-mark-feed-read-container {
display: none;
}