[Webcomic] MSPA: Let me tell you about Homestuck...

In regards to Meta's spoiler:

 Spoiler

Nah, from the wiki we see how John's choice worked out:
"he takes the option to be killed by Typheus, which would spur Dave to go back in time and become Davesprite. "

" killing John was the best way to ensure that Alternate Future Dave went through with the self-prototyping and created the current timeline"


So John's "benefit" was the creation of the new timeline. Not necessarily directly related with stopping caliborn.