Just as I start getting used to not having 3D Touch app switching so Craig Federighi says it was temporarily removed and will be making a comeback! 
@colinwalker I use that a lot and its a very big reason why I think I'll not shift to iOS 11 till they get it in there. Others I know don't seem to care as much about it!
@colinwalker Oh, that’s good news. I very quickly got used to it being there, and am missing it. I couldn’t see why the iOS 11 UI changes meant it should be removed, so good to know that wasn’t the intent.