I’m having a hunch this might be a cycle of avatars
Not necessarily. There's going to be multiple borderless card cycles in this set, but the card next to this on the list is Halo Fountain.
the cycle theory is the threshold part of this you get a different benefit per threshold
I would normally expect this to be a cycle too, although the "new threshold" might specifically be a mechanic limited to obscura (and maybe maestros) cards since it as most in home with self-mill, self-discard and things that get cards in graveyards, which in particular obscura's mechanic seems most likely to help with.
The card is good - no protection from removal is bad but you at least get a 2-for-1 with some card selection when it enters.