I'm not entirely sure if the headers the new version of the plugin uses were available before, but it sounded like they were. NR wasn't aware that the one they

I'm not entirely sure if the headers the new version of the plugin uses were available before, but it sounded like they were. NR wasn't aware that the one they were using didn't report the queueing time before the dynos and Heroku now helped them to fix that. So yeah, probably Heroku fixed their part and made sure NewRelic reflected that.