Mario Party Superstars does not have any voice chat integration, either through the game or the Nintendo Switch Online app. Instead, you will be stuck talking with a friend over another app like Discord. The only way of communicating in the game is through the use of stickers, which can be...
Another thing is that Nintendo are unlikely to want to spoil their own DLC — it wouldn't be out of the realm of possibility to have a huge franchise title be unveiled in a Direct and immediately show that they're also getting Smash DLC t...