Just earlier this week, Zwift announced that they would be increasing the member and club limit. Formerly, riders were only allowed to join or create 3 clubs, and each club could only have up to 100 members. Zwifters were pretty annoyed with this, especially when larger teams/clubs could not let some of their members into their club.
Zwift has just increased the limit of members to 10,000 and the number of clubs you can belong to to 10. This allows users to join a lot more clubs(local clubs, social clubs, racing teams, etc). This is a very welcome change, yet kids are still not allowed in clubs. Currently, the Zwift Insider club has over 2000 users, making it the largest lcub in Zwift.