Riot make a rotating game mode called season 2 and show people what the game use to be like.
Yes the game had it's issues back then but many of us long time players liked not gettign instantly killed while having 300 armor and 200 MR with 4000 health. Marksmen had to work for a late game fantasy to be most powerful. Supports were powerful without items and godly with them.
None of the champs starting with Nami active jsut to insure that no game breaking issues arise with new champs and old items. Just show the players what the game was like at the end of season 2.
And yes I know you can in fact go back to older versions of the game and play them at any time for "testing". You said you did this with the Riven CC canceling to find out when it could first be done. Consider this a chance to test the direction the game has been going for the past 4 years.