It just means that if you don’t want to update immediately, but there are things you want to upload or download, you should do that immediately as you won’t be able to once CorOS 2.0.0 is released, unless you update.
Many people do not like to update their firmware immediately, so this is an advanced warning for those users.
You will still be able to upload your Presets after updating.
You will still be able to download everything, but Starred items will move to your download queue.