A number of technical factors in the implementation cryptography-wise (homomorphic operations on blinded hashes, threshold key release via tickets) have only be

A number of technical factors in the implementation cryptography-wise (homomorphic operations on blinded hashes, threshold key release via tickets) have only been deployed in consumer-facing systems very recently. From the system as I understand it, these are fairly essential to some of the privacy characteristics they were shooting for, such as LE requiring server code to scan for users who have some amount of non-reviewed matches below the threshold.