Many early vaults had an insufficient number of rounds, and though the new account default was upgraded over time, the old vaults never were. So longer time customers were very exposed by this breach. Most impactfully by the incompetence they demonstrated by not upgrading vaults.
Wikipedia states that there were some field unencrypted, sure, but not the critical data.
More people probably lost crypto by forgetting their passwords like a friend of mine. 10k gone