Riot Games have decided to remove the biggest chat channel in League of Legends and the decision is sure to cause quite a few sparks in the community.
Riot Games made questionable choices over the course of League of Legends ' lifetime but the one they are going for with patch 11.21 is bad, at the very least. The removal of /all chat may not sound so terrible initially, due to the toxicity that comes with playing LoL but the situation the game is currently in definitely makes the removal unnecessary.
At the moment, anyone who doesn't want to be bothered by potential toxicity from the opposing team can just opt out of the /all chat in the options menu. In fact, the option is turned off by default, so anyone who has this chat on has already decided they want to see it. Therefore, when /all chat gets removed in 11.21, it will not help combat any toxicity and will only remove the option of interaction for the players who decided they want it.
Furthermore, things like joke, taunt, laugh, dance, emotes and masteries will still be visible to everyone and none of that will be muted. If an enemy wants to be toxic, they can still pester you through spamming any of those interactions.
Overall, there currently seem to be no positives to this change and it remains to be seen if the community will be oblivious to this point or if they will put pressure on Riot to revert the change.