No credit for Ramis?
He does appear though.
shareAs a CGI extrapolation of how he would appear if still alive, I guess. He has no lines, and a lookalike in shadow plays his living self at the start of the movie before being killed by Gozer.
Harold Ramis Ghost was played by Bob Gunton (Warden Norton in Shawshank, Ethan Kanin in 24) and then CGI replaced with a depiction of Harold Ramis. (https://www.mpcfilm.com/en/news/how-mpc-brought-back-the-late-harold-ramis-in-ghostbusters-afterlife/)
Also as I am aware the Reitman and Ramis family was relatively close due to friendship of Harold with Ivan. Violet Ramis and Jason Reitman are also same age, Jason confirmed being often on the sets of his father, while Violet is confirmed also visiting her dad on set. According to this article, they were always involved in the process and had to give their OK for the likeliness (https://movieweb.com/jason-reitman-talks-ghostbusters-afterlife-harold-ramis/).