Should be working today with expiration tag (when clients/relays support it). Question is if the attached content should be deleted as well - we could build blob expiration into blossom. @hzrd149
It might be a little difficult to add expiration to blob since there is no single event or thing that represents the across the network. the only thing I can think of is the server would be aware of 1063 events and any expiration tags on them