You mentioned that it will not do this, if it is not safe. I can understand when macro is running, you can't really restore that. But you also mention if something is not saved. So, if you type something, doesn't hit Save button and leave Pc idle, so it locks, Office will not be able to update? In that case i don't see how it is different from current situation when it updates when user is idle.
Or was it that before that Office would never try to update if user is using it? I think i remember Office updating on me while i am using it and rebooting my apps, so it doesn't seem true.
Or will it try to update now even if document is not saved and then restore it to previous unsaved state? Which would be a more robust approach and would indeed increase speed of updates as many users do not press Save button that often and leave PCs running idle for hours with all apps and documents opened.