Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn.
Please fondle my bum.
There are more encounters that make you a member, some of which are on expansion boards.
All of them (if any) are on the expansion boards, sonce Miskatonic doesnt give you any encounter cards for the Arkham board.
It seems to me that the chance to join the cult is still as slim as it was before, which makes the goat next to useless (if not plying with the herald from tho Goat). So, it stays at is was before