A lot of the old 5 stars got retired. Sum Sam was actually fairly weak compared to the other 5 star counterparts of the day (DJ Korr, General, Guru) and it's possible he got retired for lack of interest or storyline purposes. (There is a sort of storyline going on.. though it's hard to say if anyone outside of Fraggle and the card designers know what it actually is)
One has to assume Sigmund was retired for the same reasons. No one played him (of course if that was the sole reason entire clans would be retired), he was weak for his stars and stats (again many characters fall under that category as well). Really unless the people who made the decision want to come forth with the answer it's something that we can only speculate on.
Ah right thank you storm wind , i was browsing the market and lookin at the old CR's and noticed they were some whe wen't overpowered or 4/4 ish , since the over powered ones were banned along time ago is there going to be replacemnets for card's like Guru Cr and General Cr i know they have with Kiki and Rass but what about the other old collectors?
Again, I don't have the answer to that. I'm not privvy to the card creation secrets and even if I were I couldn't tell you if DJ Korr or General were making a return
Disclaimer: NO.. that is not some backwards way of me starting a rumor that DJ Korr or General (or any other CR) will be remade. I honestly do not know if they will or not. Yes, it is a possibility, but no official word of this has reached me. So don't start saying "An Admin said DJ Korr (or insert CR here) is coming back. It's simply not true.
Yup for instance Kiki when he was about to be broght back the admins made a special announcement that the wildest fight in UR is returning. For Beserk Girl I think she was re-released before New Year as the 200th character. And Rass was re-released because of Summer. I wish UR would also have a Halloween and Christmas Event this year. Last year they said that they were busy and was not able to make a event hope they will have time this year.