My newsletter Workflows are broken because they read and write to Dropbox. Currently Dropbox is only supported through the Files browser. You can’t have a Get File step that uses a specified path in Dropbox. You can in iCloud, but it looks like the path may be locked to the Shortcut’s folder.
I also thought Siri might be able to pass the current object, like the open Safari page, to a shortcut, but it doesn’t. It would be nice to tell Siri to “save this” and have a shortcut fire that added it to a note or saved it in reading list. I would imagine that will come.