ErmengardeStopSniveling said: "jordgoldberg said: "Been trying to make sure I understood the phrasing of this right since I'm dying to see him. Is Mulaney only a part of the show for the first 5 weeks/this cast, or is he in the cast for the whole run? Killer cast regardless!"
There will be another round of replacements after Jan 12:
The production, which is slated to run for 10 weeks, will begin performances on Dec. 11 at the Hudson Theater, with an opening night yet to be announced. Mulaney, Kind and Armisen are set to be in the show through Jan. 12. Goldsberry will perform through Dec. 30, with the “S.N.L.” comedianChloe Finemantaking over from Jan. 2 through Jan. 12.Casting for the rest of the run will be announced later."
It's actually not clear from this article whether Mulaney is starring in the entire run and just the remaining cast is rotating. Although it does say, as quoted above, that "Mulaney, Kind and Armisen are set to be in the show through Jan. 12," it earlier says that Mulaney "will lead an ensemble cast of four actors" and that "initially, Mulaney will be joined by" Kind, Goldsberry, and Armisen. That could be read to mean that Mulaney is there throughout and will be "joined by" other actors at later dates.