Microsoft Lists now offers an admin control to hide real-time collaborators at the site collection level, available worldwide since early December 2024. Admins can use the PowerShell command 'Set-SPOSite' to enable this privacy feature. No action is required before the rollout, but preparation steps are advised.
Applies to: SharePoint Online
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).