Does Ponyboy ever share Johnny’s message about staying gold with anyone else in The Outsiders?
Yes, Ponyboy does plan on relating Johnny's message about 'staying gold' to other people, as revealed in the final chapter of the novel:
"I could picture hundreds and hundreds of boys living on the wrong sides of cities [...] Someone should tell their side of the story, and maybe people would understand then and wouldn't be so quick to judge a boy by the amount of hair oil he wore" (179).
Ponyboy contemplates the importance of telling the other boys' stories after finishing Johnny's letter. He wishes he could tell Dally, knowing and hating the fact that it was too late. After considering all the other boys who might need to hear a similar message, Ponyboy picks up his phone and called his English teacher, Mr. Syme, wondering about the required length of his English theme essay. The reader can infer that Ponyboy plans on telling his and Johnny's story for his English paper that is due.