User blog comment:TahuMaster0fFire/Which Series 4-6 tribes do you think will get more members in Series's 7-9?/@comment-24414949-20150217203140

Either it's the Orbitons, the steampunk tribe, and the construction tribe, or the Cragsters, Fang Gang, and Spikels. (If the series expands to 12 waves, chances are we're getting 2016 Electroids.)