The latest update adds more security options to ensure only authorized users and devices can access a business's Slack workspace. The new features include the ability to require a secondary authentication method on mobile devices, such as using Face ID, Touch ID or a generated password, and the ability to block file downloads or message copying. This should stop employees copying messages or files onto unauthorized devices.
There's also a domain whitelisting tool which limits which Slack workspaces can be accessed from a network, to stop employees signing into unapproved Slack spaces. That will stop employees from signing into other business's Slack workspaces while they are at work.
More enterprise features will be coming later this year, like a remote wipe option which clears a user's Slack sessions if their device is lost or stolen, and an option to control which browser a device uses to open links within Slack. To ensure people aren't using Slack on an insecure OS or running an outdated app version, there will be jailbreak detection and an option to force an app upgrade.
Finally, Slack will add an option to block file downloads from desktop machines outside of approved IP addresses from next year.