Is there a way to make a channel where members can post but not see other members posts? For example, I would like to have members send message of seminars they would like to attend but I don’t want everyone else seeing other peoples seminars.
This ought to be coming in the future with the integration of Kaizala. Kaizala has something called Hub and Spoke groups where individual members can message an admin but the members do not see each others messages.
So Hub and Spoke groups should be part of Teams at some point. Until that time it is a workaround as others have suggested - Forms into a single locked down Team/Channel via Flow would work. I wrote a blog on this once -