People will join and rejoin. It was like that for all of D1 before this clan cap crap. With two clans no one will ever be left out and with how easy it is to level up, people will always get rewards.
If the stupid 100 person cap wasn't a thing, I would be in BG prime. I miss seeing the BG by my name or seeing 5 BG and my 1 Atma in a wipe screen.