To be hopefully crystal clear: Overwatch voice chat is a privately hosted service that’s built to be used by players during overwatch games. Blizzard moderates the content of that chat to remove disruptive content, where disruptive means “chat that makes people not enjoy playing overwatch”. In general, that’s people shouting slurs at their teammates or rambling about nonsense. Changes like the phone number requirement are part of their approach to expand the preemptive blocking of this activity. And I am fully in favor of them doing this, because it improves the quality of the game.