Experience Systems Change (Idea)
I understand from the changes that have been explained throughout Rioter comments and the video posted in 'RIOT PLS' that there is no plan to adjust accounts levels for those who've played for well past the time it took to initially become level 30. From the video it is made clear that the IP you would normally get post-game is now allowing you to level up. However, this is done so under the facades that this is an experience system - which you can not argue since it would never actually be an accurate system to define a player's actual experience or, in reality, devotion to this game.
Realistically speaking the idea of this new system is to combine two things that haven't really belonged together for a long time - the old IP system (which really only proved you got your win of the day/played a long game) and the old XP system which proved you are developing as a player. Of course the latter was very limited since it capped at level 30.
As stated in the video, this new system rewards the player with the ability to level indefinitely (instead of gaining IP since it will be leaving) - resulting in an unlocked chest (which increases in the quality of drops by higher level). In theory, this sounds great and I generally think this is a smart way to reward players, but this completely undermines the role that the player level actually plays - again because it will never actually be accurate. If anything I really think you need to rename the term "level up" to something else like "triumph score" where it is clear to the player that this system is about playing and not necessarily experience. This also allows RIOT to reward those for winning - although I could see that being a turn off, but I guess traditionally you would get IP either way, so you could explain it as: less leveling up for losses and more for wins.
Subsequently I would absolutely love if you created as secondary experience system, which you could again rename to some thing like "dedication score" there would not necessarily need to be an out of game affect with this system besides a number on a profile, but this could be represented as an emote that a player could show in game. I really hope you will take this into consideration (I realize time is limited), but I honestly know that I and many other players will be hurt if this isn't actually addressed. I feel like this solves all issues players have - not runes reforged related.