i agree if Riot has a separate team that mainly focuses on created Animated short movies or mini-series like with Rek'Sai's teaser trailer & with Bards recently uploaded trailer (which fcking looks AMAZING) & like fully comment in releasing content every week or so then yeah i think this would be a highly recomandible & if these animated short movies or mini-series get extremely popular from the people who enjoy the game & wish to own these it could be highly profitable
although i think Riot should not "sell" their animated products instead keep them in playlist on their own Youtube Channel where people can watch them at anytime, plus if Riot made these & post them on Youtube we the players of the game & watchers of these videos can give the people at Riot feed back by our Comments on what else we would like to see happen or have suggestions for what Riot could think of making. that way we the Players & the people at Riot can be closer to make League of Legends even more better in the future.