On the teams I've worked on, I've usually always been part of a public Slack channel (with managers, product, designers, various stakeholders) and a private slack channel which is only engineers.
1.) I think the private channel makes people more likely to ask the "dumb questions", be more frank, and generally more communicative: do you agree?
2.) Should engineering managers be part of the private channel?
In general, I'm curious what HN thinks about this paradigm!