From what I can find in the trade registry, the Order of the Black Cross, and its executor corporation Dark Seraph indeed seem defunct.
An alarming number of capsuleers that were registered with them have been biomassed and/or have been stricken from the Record. It looks like there was a final purge somewhere around or just before YC112, not just a disbanding. These folks didn't retire, they were eliminated.
There's no more trace of lord Jeserat Verisum, or Revan Neferis (who perhaps became his wife and a lady of the fallen House).
A few members of the Order got out, and remained active. There's only one of the maybe more prominent members that managed to escape: ms. Verjigorm. She's a convicted heretic and now a pirate and has shown signs of activity all the way up to YC 119.
To my surprise, I found that a former member of the Order of the Black Cross has joined SFRIM, staying there up to June last year. Mr. Kazuma Ry. I pulled up his interview. Too bad that back then no-one asked about prior associations with known heretics... Nothing special was noted in the interview, it would take a skilled exegete the transcript may reveal an undertone of the Order's heretical beliefs painted over with the veneer of tolerance.
