Avatar custom font design by Swell Type
How I made Letraset: an interview with Freda Sack
Papyrus: The Power of a Bad Font - First American Art Magazine
An Audience With The King: James Cameron Interviewed By Hollywood's Finest
After writing and shooting my video (but while editing it), this article was published (https://www.theringer.com/movies/2022/12/14/23507513/saturday-night-live-papyrus-sketch-avatar-james-cameron) which contradicts that. To be fair, he may not have been conscious of choosing Papyrus himself in his draft scripts.
I [heart] Papyrus: Interview with Papyrus creator, Chris Costello
Papyrus font creator reacts to viral "Avatar" skit from "Saturday Night Live"
Chris Costello - the creator of Papyrus \\ Ep. 94 Creative Waffle