The developers of Valorant had promised the players at the end of the beta. The latest patch added a new feature to allow you to forfeit the game if one of your teammates chooses to quit.
It's thanks to a datamining of Update 1.01 that this new feature was discovered, since it wasn't included in the patch notes. Anne Donlon, Executive Producer for Valorant, commented on the tweet to say: "Nice find! Not live in this patch, though. It's a complex feature and it's still being tested."
You can roughly see what it will look like with the possibility of voting to drop out for the next round with the famous "FF" (Forfeit) of League of Legends. It will only be available from round 8 and limited to one use per round, with the aim of preventing players from misusing it.
No date has yet been announced but it's likely that this feature will be available at the same time as the Competitive mode to ensure the healthiest possible game experience.