Mistral support just confirmed that the org-wide toggle was removed from the Team plan earlier this year and made exclusive to the enterprise tier. I bet that if you signed up earlier, they didn't remove it from your account, but it's not there for new customers. Which explains some of the confusion here.
Also explains that the community support in Discord insisted that the toggle should be there, moreover they told me the individual toggles on the user's pages wouldn't do anything because it defaulted to "off" for any organization, as per their docs until 2 days ago. But that changed.