Good news! This is in the works.
The option to “discard” suggested contacts in your chat list is rolling out to users. We will be making further changes to make suggested contacts more relevant for new users in the future as well, so marking as partially completed. Thanks for your patience with this one.
~Alex & the Teams teamAnonymous commented
Agreed, please at least allow us to remove suggested contacts that make no sense.
We acknowledge the customer demand for Private Channels and have been hard at work on it. Private Channels is currently in preview with a select group of customers. We expect to release the feature to the public later this Fall, and will update here when we are starting to roll out to all customers. We appreciate all the feedback you have provided to us on this forum and thank you for your patience.