In most other games, to enter the "Elite" mode of content you have to unlock access somehow. Usually by participating in a trial or other game test to make sure you have met the minimum threshold to be in the encounter.
A door blocking boss that requires a minimum DPS or does a certain level of damage that you must be able to survive, for example. Perhaps a team event that unlocks access for everyone on the team if they can defeat it, set to about the same difficulty as the content it unlocks.
Pretty much every other MMO does this so that the players who are playing this content can be assured that anyone else playing at least has the core mechanical ability to participate, even if their player skills may be lacking.