Is putting your mastery emote on an ability considered "trolling" and subject to a ban?

If so, is there any documentation from Riot explicitly stating this? I OTP Eve and I have my mastery emote set to go off when I press W. In the search to find out why I was banned, specifically, it was suggested by a friend that mastery emote spamming has led to some players being banned. I personally have never heard of Riot saying or suggesting this could be a punishable offense so I'm looking for more insight. I got the idea after I noticed a Sona who had it on her Q. Being an Eve OTP and considering she isn't played often I consider it a point of pride, my 380k mastery points on her. I searched on how to do it and found this almost 1700 upvoted thread- https://www.reddit.com/r/leagueoflegends/comments/3mwvls/how_to_set_your_champion_mastery_emote_to/

Is this a potential reason I was banned and if it is is it fair if there if there is no Rioter on record as saying it is punishable?