You can no longer report a teammate for refusing to communicate post game.
I let you in on a secret, sunshine:
#You never could.
The "Refusing to communicate" - report was always a placebo.
Designed at first way back in the early days as a feedback-feature for Ritos server department, to figure out which realm-communities had trouble communicating and tweaking matchmaking algorithms accordingly.
Later it was left in as a lightning-rod for false reports, giving raging kids a placebo-button they could press to vent their anger. Frankly, I don't know why they didn't keep that non-function, because it was a great way of fooling all these raging report-trolls.
In any case, no one was ever punished for a "Refusing to Communicate" report.
Ever.
And yes, this was confirmed by Riot
"Secondly, failure to communicate isn't a bannable offense. We do have the option to report along that ,but we are using it to inform to what extent users are experiencing adverse effects from foreign players. We are currently researching some options here to mitigate this stuation, ranging from some new UI features, to some matchmaking features. Additionally, we hope to launch in other territories soon, which will reduce the % of users on the US servers who do not speak English, because those users will be on their own local servers."