Although we use the term Orpheotelest (pl. Orpheotelestai) to refer to the highest grade within the Starry Bull tradition it’s not something that our Bacchic Orphic predecessors employed.
While an ancient term meaning something like “Orphic initiator” or more broadly “expert in Orphic rites,” all the instances of it come from outsiders chronicling the activities of a class of mendicant religious specialists. Although our knowledge is mostly formed by these outsider accounts, in the rare instances when they are permitted to speak for themselves it seems that they favored terms such as hierus/hiera (priest/priestess), magos (magician) or mantis (diviner) or else they were functionaries within a thiasos (private religious association) or served at some sanctuary and held the corresponding titles.
Indeed, it can be difficult to identify those with Orphic sympathies unless they explicitly identify as Orphikoi (rare) or (more commonly) attribute their ritual or theological texts to Orpheus or Mousaios. The subject matter – mention of Orphic divinities, a concern with pollution, ancestral guilt, averting daimones and other sources of bad luck, illness and the like, spiritual liberation and eschatology – can give it away, but not always as these were also concerns of many contemporary figures and movements.
So why do we use it? Well, we needed a term that encompassed more than just “priest” or “diviner,” and wanted to keep it within the Mediterranean milieu, so “spirit-worker” and “shaman” were out – thus we settled on Orpheotelest, despite its “outsider” origin. Especially as some of the earliest users of it may even have possessed insider knowledge – Plato, for instance, is constantly quoting or paraphrasing Orpheus, employs special mystery terminology and was an initiate in several traditions that were strongly influenced by Orphism. Indeed, just as one may speak of a “Thracian Orphism” or a “Bacchic Orphism” there is also a “Platonic Orphism,” which is probably the most prolific branch within the contemporary Hellenic polytheist movement, both in its native Greek and broader Anglophone varieties.