I googled "moodle bulk enrol" and got to https://docs.moodle.org/35/en/Bulk_enrolments. It does say "Type: local plugin" in the uinfo box, but I only noticed if after googling for "moodle bulk enrol option missing" and found this thread.
Enrolment
Unable to bulk enroll students
Keskustelu on lukittu, joten et voi enää vastata siihen.