The concerns you list don't stop this from being a good thing, I agree. My bigger concern is what BoAs rate of low-wage direct employees versus contractors looks like, and will look like in the future. The overall trend seems to be that contracted service work is paid somewhat worse than direct, but also faces no benefits, high firing rates, and far nastier working conditions. I don't have numbers on BoA, and I doubt they'll publicize them. But my concern is that moves like this (without a corresponding guarantee for contractors) create an incentive to offload ever more work into conditions that might be even worse than the current state of affairs.

I don't want to undersell this, though. I doubt bank tellers will become contract labor anytime soon, and this will actually represent a significant raise for them.