U chose group and role. If some users in some projects have this role and member of this group, he’ll suffer from becoming a watcher of every issue (except thous that unchanged).
Redmine 4.0.* and more if syntax woud not change much. Юз ит иф ю брейв энаф :333
“Default watchers”
Automatically adds chosen group’s or/and riole’s users as watchers.