So I took a look at my apps running in the background to test this and they neither refresh or reset.
ios became better at handling refresh but here is what you are not getting to clarify.
Apps that are usually do not get updates from somewhere like Pages or E-mail and most of what you showed in your video get saved in what they call a saved state, it means when you go back to it , it reloads exactly to where it was before.
There are other apps that do refresh and do no have a "save state" . For example, the YouTube, Instagram, and Twitter app. If you keep them long enough in the back ground and come back to them, they will refresh and load whatever new info/news/posts are made. This kind of behaviour usually does not happen in desktop apps , as everything remains where it was prior. Some other apps do refresh maybe like the Wikipedia app where if you keep an article in the background and come back to it later on it would refresh to the Wikipedia home page.
just clarification.