I've known several families that had kids in the Yu Ying Chinese immersion charter school in Washington, DC. One's kids are still in it, more have moved to other charter schools or to private schools. I've never asked the movers why.
I’m a parent of a child at the Oakland school. I believe the DC school is unaffiliated. I’ve heard it’s common for parents to take their kids out because they decide being taught in multiple languages where the main language is their child’s second language isn’t working for their child.