We are committed to keeping the world of Sanctuary a safe and fair place for all players, and our Game Security team constantly monitors for cheats and unauthorized modifications. All Diablo IV players agree to the Blizzard EULA as a condition of playing the game. The Blizzard EULA explicitly prohibits cheating, bots, hacks, and any other unauthorized software which automates, modifies, or otherwise interferes with the game. This is important to players’ security as well as the game’s long-term...
Have they said anything specifically about wine/Proton?
They haven’t but I don’t think that applies here as it shouldn’t modify any of the game files. I haven’t heard of it being an issue with other games either but I also don’t keep an eagle eye on that stuff.