I'm a currently working software engineer from Lambda, who knows other people who succeeded at Lambda and other bootcamps.

The TA thing, a TA doesn't teach, a TA pretty much grades/code reviews. They answered questions. (I did this while I was hunting for a job).

They also don't count that towards placement.

I have an IS degree, but some other people I know succeed with pretty much anything you can think of. I don't have enough of a sample size to know if we're all just exceptions or not.