Whether the game is in suddendeath or in matchpoint is calculated at the start of a new round server side. Clients then use this cached boolean to display this information in the top hud. If a value that determines this state changes mid round, the new value will be used to determine the outcome of the round on the match when the round ends, but the text in the top hud will still use the old value until the cached value is updated next round (if next round ever comes)