Sure, I believe it happens in pockets, though it's very clearly spelled out company policy that this process is not a second interview. But people are people and supply/demand rules apply here as well. It also more often took took the form of who a hiring manager might reach out to vs not. As a hiring manager, I and my peers engaged in good faith AFAIK with bootcampers that reached out directly. Given the many openings in our growing teams, doing otherwise would've been foolhardy.