While refraining from divulging any details, it appears that the Overwatch / Blizzard CS folks will let you know the impact of reports made against other players. "We know that our players often wonder about what happens to the people they report. In this case, your recent report led to an action against that player and their account."
The post was made by a player who had reported a pair of other Overwatch players that were also reported by several others. According to Reddit, one was an XP farmer using a bot script, the other using an "aimbot" program.
Thank you for helping us keep Overwatch fair and fun by reporting players who you suspect are cheating or exploiting the game to gain an unfair advantage. Your reports help us identify players who violate our fair-play policies and disrupt the game for others, making it less enjoyable to play.
We can't provide specific details about the penalty type and duration, but we hope that seeing your reports have an impact will encourage you to send similar reports in the future. Keep up the good work, and thank you for helping us make our games a better place.
Check out the Overwatch Reddit to read up on the conversation.