https://www.youtube.com/watch?v=WW_R3sYJ96A&index=1&list=LLBL_amJX0i2J_xl8p_qEp2w This was a video that was posted in early march, with either hidden coded animations within the game, or fanmade animations of mastery level 6 & 7. Also, Riot them selves said they were planning on implementing more tiers and rewards upon the mastery system receiving good feed back. are we going to get that or no?
Would be nice, if Riot give top lvl mastery for top 100 players for each champion. 
I'm pretty sure Riot will implement more mastery levels sometime in the future. Maybe they are brainstorming what rewards for tiers will be, or maybe they are putting this on the back burner as more important things have come up. Or maybe they are working on it as we speak. All that we can do is wait patiently and give Riot feedback about the stuff they are working on atm.
