I'm guessing they're trying to "clean up" situations where people have lots of shared libraries cluttering up their sidebar. I don't mind it that much since I rarely go into a specific library since all of the content is combined on the home screen. But yeah it does add extra friction if you want to go into a specific library.

I am more concerned that, based on the forum comments, they are making it harder to hide the ad supported content and rentals, as you can't unpin those from the app and instead need to go on desktop and disable them from your account settings. And it sounds like they don't plan on adding the ability to unpin Plex content from within the app. Maybe it's not so bad since changing your account setting is more permanent and doesn't need to be done every time you log into an app on a new device, but I don't like needing to do it on desktop instead of having the ability within the app.