I think pro play should "never" be balanced
There is too much of a difference between pro play and normal play. that any buff /nerf directly linked to proplay has 0 benefits for us as normal players. When sejuani and tp is nerfed, it doesn't impact is any positive way. There are no sejuanis in my game that are so dominant I cant function, nor is tp so viable that it will always be taken 100%.
What I'm trying to say, is that proplay balancing is actually disruptive to the rest of the game, and causes unnecessary ripples and destructions to the status quo of every other player. Unless your part of the top 1% of players, any changes made directly for lcs has almost a negative impact to your game, cause you have to spend more time fighting against the changes and trying to adapt.
The rest of us normal players don't play at a pro level, so its quite disingenuous to us, to be forced to go through changes just because 5 extremely skilled players, who practice with each other every week, in a team setting, vs the very best in the world, use a few repetitive or hard to beat strats.