Expiry is at end of era, when it is pruned if expired. Allows more data to be purged. Note: EE doesn't have a concept of 'era' so it will be a forward calculation of block-time. all post 2..0 urefs will be removed from tip when expired.
The uref expiry epic was removed from 2.0 scope well over a year ago. Thus all of the items in it should also have been removed from scope rather than allowed to just roll over infinitely.
Expiry is at end of era, when it is pruned if expired. Allows more data to be purged. Note: EE doesn't have a concept of 'era' so it will be a forward calculation of block-time. all post 2..0 urefs will be removed from tip when expired.