since they released tickets (https://www.ticketmaster.es/artist/valorant-champions-tour-entradas/1238204), I think we now have a good idea on how it's gonna play out.
5 day swiss stage followed by 4 team double elimination bracket
I assume for the swiss stage, it'll be each team playing 2 seeded matches. Two 2-0 teams qualify for playoffs, two 0-2 teams are eliminated. 4 1-1 teams each play another game, winners go through, losers are eliminated. This means 10 matches are played, 2 matches a day.
Playoffs are straight forward as described in the tickets.
Format is like champions group stage but with an extra grand final.
Day 6 - upper bracket semis
Day 7 - upper bracket final + lower bracket elimination
day 8 - lower final
day 9 - grand final