Oh it certainly doesn't require a complete search history. That's why Workspace search history will have 18-months retention by default (which is aligned with Google's policy in general) that you can change down to 3 months if you so choose (and if your Web and App Activity setting has retention set to 3 months, we'll also automatically carry that forward to Workspace search history). You can always turn the setting off.
But, being able to better help users find recent files or emails does require storing _a_ history, which we can't do if the setting is off.
But, being able to better help users find recent files or emails does require storing _a_ history, which we can't do if the setting is off.