Is All Chat Disabled In Euw?

The only function that won't work is the conversation in its entirety. Your enemies will continue to be able to hear and see your emotes and champion mastery (unless you have them muted), as well as your spam of CTRL+1/2/3/4. The talk at the end of the game will continue to be cross-team. In the team chat, allies will continue to be able to communicate with and cooperate with one another.