There was no reduced latency. The article title should be something along the line of:
"Bad architecture resulted in a hard-to-troubleshoot bug"
Really, the title should say "PR_SET_PDEATHSIG doesn't mean what you think it means."
The man page for PR_SET_PDEATHSIG: "The parent-death signal is sent upon subsequent termination of the parent thread and also upon termination of each subreaper process"