ZeniMax posted a new community Q&A today about Craglorn. The studio said that there will be rewards for everyone, not just those who make the leaderboards. Players can expect to spend between a half-hour to 1.5 hours per trial with 60 resurrections allowed for the group as a whole, and they will need to be at least veteran rank 11 to participate.
Some players had asked what these Celestials are, to which ZeniMax responded, "The Celestials are a new concept based on the existing lore of the constellations in The Elder Scrolls games. There's quite a bit of lore in Craglorn that will be interesting for fans to discover."