Earlier quoted context omitted.
But they're not blocked and they are asking for help. They're just doing it via DM instead of in the 'public' chat. Slack is literally telling folks: 'You are holding it wrong'. In reality their product isn't that great for q&a or knowledge sharing. Horrible search, bad notification, high noise to low signal.
They are blocked when the one person they DM'd ignores the message because they are busy with other stuff.
And quite often, you get better and faster response when you ask a person instead of forum.