Without a lot of the project reports, the manager would honestly just have no idea what's going on. I recently moved into management, and one of the challenges I'm trying to balance is how to be aware of my team's progress without wasting their time or being a bottleneck for them. It's a legitimate problem which is often tackled poorly.
At least in the case of software development, which seems to be what Scrum is targeted at, you get the project reports for free by way of the commit log.
That said, the 12 Principles of the Agile Manifesto offers another solution: Get rid of management entirely. It states that developers are best to work with the rest of the business collaboratively. Which is the irony of Scrum claiming to be Agile: Only management wants to use it, defying Agile to its fundamental core.
regardless of "process", work items should be tracked (in the problem solving record for our future selves sense, not time keeping sense), so you can follow those. If you're a non-technical manager, then either a) the implementation goes super smoothly and the estimate the dev team initially gave you is all the progress update you need, or b) it doesn't go super-smoothly and you should be involved in any discussions that arise. If you find yourself asking "when is it ready?" you've likely gone astray.
