this is something we're definitely working on, there's a few things going on at the same time.
1. The CC app itself gets updates. If you're a purely Illustrator user you might not notice (or use! which is ok!) the features we've added, but it now has the ability to add custom fonts to your Adobe account, we've added new tutorials, and community features, support for CC Libraries, and a new unified search. One of these new features is notifications, which is #2.
2. Our notifications can be a little noisy, especially if you're not a frequent user. In the Creative Cloud app, you should see under Preferences > Notifications, the ability to select which notifications you want. So, if you want to disable App update notifications, you can.
3. On top of the features, there are some update/sync processes that go on in the background that won't function. Our current messaging just says "pending installations" which doesn't cover it all and we've heard a lot of feedback from users internally and externally about it. We're going to make that message more tailored to anything that's actively going on, and if there's nothing, allow you to close the app silently. To double check that nothing is actively installing, you can check the cloud icon in the top right to confirm. If there's nothing there, you can close it with confidence that it isn't installing an update.
Hope to get these enhancements out to our user base soon. Thanks for your feedback! Please note, we do actively track anything we see on our User Voice (http://creativecloud.uservoice.com) and try to engage on social media, in case you'd like to keep giving us more feedback outside of HN. Thank you!