Riot Games has issued a statement revealing that the representative from the Vietnam Champions Series (VCS) will in fact not be attending the League of Legends Mid-Season Invitational 2021 due to "national travel restrictions related to COVID-19".
To make up for the loss of the team, Riot has stated that no replacement will be involved, and that Group A will play with three teams, with the top two advancing to the next stage instead of having four teams, as the other two groups do. You can see the updated MSI 2021 groups in the graphic below.
MSI 2021 is also expected to start on May 6, 2021, and will pit the top teams from each region of LoL esports against one another for a regional team spot at Worlds later this year, alongside a pretty hefty cash prize. You can catch the action when it starts over here.