Olivia Marcum, a young actress from “Matilda The Musical,” has joined the cast of “The Exorcist” sequel. She will collaborate with the previously revealed cast members of Lidya Jewett’s “Good Girls,” Ann Dowd’s “The Handmaid’s Tale,” and Academy Award contender Leslie Odom Jr.’s “Glass Onion.” Replacing her role as Chris MacNeil from the 1973 original picture is Ellen Burstyn. The next entry in the franchise from Blumhouse, Universal, Peacock, and Morgan Creek will mark the beginning of a brand-new trilogy. It also appears to be a straight sequel to the original film, “The Exorcist,” recasting parts two and three. In…