Europe has 6 groups of 7, with 2 teams advancing from each group, for 12 teams in the second stage. Groups of 7 take 7 weeks, with one bye week for each round.
The Americas and Asia-Oceania have 3 groups of 6, with 4 advancing from each group, for 12 teams in the second stage. So it looks like the 2nd and 3rd stages will be the same format for both Europe and Asia and Americas. It appears that the extra bye weeks are added so that the continents are in sync for the 2nd and 3rd stages.
Note that the format for the Americas and Asia-Oceania can be expanded to 3 groups of 8 (18 to 24 teams) without changing the basic format.