Many organizations are choosing newer, more secure and user-friendly collaborative modalities over pre-pandemic solutions: guest access, guest access and shared channels. Slack’s version of shared channels, Slack Connect, launched in June 2020, opening the shared channel floodgates, and allowing for easy external communication. Microsoft Teams and Slack are the proverbial nail in the coffin for guest access ‘ with shared channels poised to rise from their ashes. Microsoft teams will be directly integrated into the upcoming Windows 11 update, making joining Teams meetings both easier and quicker.
Source: https://www.helpnetsecurity.com/2021/08/05/shared-channels/