I believe the Imms aren't currently interested in working on Lich quests at the moment actually. I would point at a post on the Officials under gameplay where someone was asking about Lich quests. The Imm who responded did not say no outright, but kind of hinted that no one was currently doing them because there are two automated systems set up. Lich quests are, of course, immortal driven. There was no real explanation given. I would assume they are all busy doing a bunch of stuff and that if someone wants to lich they would have to have superior role and roleplay. I have a guess on who made the post on officials, and their current active player (if I am right) did a very good job with roleplay, probably has a good role, and seems to have a good deal of immteraction. Since I have returned to playing a couple years ago I have seen 2 mummies and maybe 6 wights. 3 of those wights are current. 2 of the old ones were myself and my brother. That being said, I don't know what it will take before you see another Lich in Thera.
I, too, miss Istendil. Knew him as Dreadlord before he became, and as Emperor after. That's how the F@#k old I am.