There is no Check for Updates menu items on the macOS desktop app, nor is the desktop app available in the macOS App Store (where it would automatically update from if it were there). I see Mattermost Inc already has an app in said App Store but not Mattermost desktop. I only discovered there was an update when a colleague notified me. Could one or both of these things be done please?
This feature was initially available before it gets removed in Mattermost Desktop 4.3.
We are keeping track of this in the following JIRA ticket:
Please add the ticket above to your watch list to keep yourself notified for updates when the feature is going to be available again. Hope that helps.