Madrid Format

I don't know how they're going to do it either, but the Swiss mode is like this: imagine that from the first round each match will determine who your next opponent will be, whoever wins their first match will go against another team that also won their first match ( and the same thing for those who lost), this way the teams will always face another team that has the same number of wins and losses
my guess is that they will eliminate the teams that don't achieve any victories and then move on to a normal Bracket

its a format what counter strike have been using

so basically every team face against each others in their own group until they get the amount of wins they needed
(loser vs loser, winner vs winner)

in cs 3 wins and you qualify from group
bo1 in lower stakes matches and bo3 in higher stakes matches and if teams go undefeated they get highest seed