The users in question never opted out, their domain admins opted out of a different feature.
And the corollary equally applies: it's a trivial feature with no privacy impact, why require opt-in. I don't want to be spammed with opt-ins every time every app I use adds a trivial new feature. I'd be clicking a dozen boxes a day.
Keep in mind all the user data collected is still under the workspace data use agreement which is very strict and disallows using the data for pretty much anything that isn't directly providing that service to that user/organization.
