No problems with rights. They have a consortium that shares the profits and
also controls how the writers can handle the characters created by other
members (which is why Croyd still appears in the books).
The big problem is that the series keeps getting optioned and then languishing
in developement hell until time runs out for developement. Melinda Snodgrass
was even tapped to write the screenplay for that last attempt.
It seems they keep trying to turn this into a series of movies instead of
doing a TV series. The same thing happened with the Sandman comics until
Netflix let Neil Gaiman do what he wanted. (I think Gaiman has written dozens
of treatments in the past).